Collapse Behavior of Pipe-Framed Greenhouses with and without Reinforcement under Snow Loading:A 3-D Finite Element Analysis

The present paper first investigates the collapse behavior of a conventional pipe-framed greenhouse under snow loading based on a 3-D finite element analysis,in which both geometrical and material non-linearities are considered.Three snow load distribution patterns related to the wind-driven snow particle movement are used in the analysis.It is found that snow load distribution affects the deformation and collapse behavior of the pipe-framed greenhouse significantly.The results obtained in this study are consistent with the actual damage observed.Next,discussion is made of the effects of reinforcements by adding members to the basic frame on the strength of the whole structure,in which seven kinds of reinforcement methods are examined.A buckling analysis is also carried out.The results indicate that the most effective reinforcement method depends on the snow load distribution pattern.

Research on cognitive load evaluation with subjective method in manual assembly

Subjective scales have different kinds of applicability in diverse fields.This study intends to implement a quantitative approach to determine the applicability of subjective scales in manual as-sembly work and evaluate the cognitive load of assembly workers.A multi-scale research paradigm based on subjective evaluation method is proposed.Three typical task stages are extracted from the process of assembly work.The National Aeronautics and Space Administration Task Load Index(NASA-TLX)scale,PAAS scale and Workload Profile Index Ratings(WP)scale are selected for the design of 3×3 multi-factor mixed experiment.The power spectrum density(PSD)characteris-tics of electroencephalogram(EEG)are utilized to identify the difficulty levels of the three task sta-ges.The relevant indicators of scale applicability are assessed.The results show that in terms of sensitivity,NASA-TLX scale reaches the highest sensitivity(F=999.137,P=0<0.05).In terms of validity,NASA-TLX scale possesses the best concurrent validity(P=0.0255<0.05).In terms of diagnosticity,NASA-TLX scale based on 6 dimensions takes on the best diagnostic performance.In terms of subject acceptability,WP scale performs the worst.According to the analytic hierarchy process(AHP)model,the applicability scores of NASA-TLX scale,PAAS scale and WP scale are determined as 3,2.55 and 1.6714,respectively.Therefore,NASA-TLX scale is regarded as the most suitable subjective evaluation questionnaire for assembly workers,which is also an effective quantitative evaluation method for the cognitive load of assembly workers.

Shielding AZ91D-1%Ca from corrosion through ultrasound melt treatment:A study for stent design

Magnesium-based materials show great potential for producing biodegradable stents,but their high corrosion rates are a roadblock.This study investigates whether ultrasound melt treatment can change the corrosion response of an extruded AZ91D-1.0%Ca(wt.%)in Earle's Balanced Salt Solution by tailoring the intermetallics'morphology in the as-extruded state.The results showed that the wires from ultrasound-treated ingots corroded faster than non-treated ones in immersion for up to 6 hours.This trend shifted for longer periods,and ultrasound-treated material showed lower corrosion rates and uniform corrosion,while the non-treated material displayed localized corrosion signs.Tensile testing of the wires demonstrated that immersion in EBSS lowered the tensile strength and elongation at fracture due to material degradation,regardless of the processing route.Nonetheless,this decline was sharper in the non-treated material.These findings suggest that ultrasound melt processing can be a promising method for improving the corrosion resistance of magnesium-based materials,paving the way for their use in manufacturing biodegradable stents.

Captcha-Based Honey Net Model against Malicious Codes

The rate of passive and active attacks has been on the increase lately affecting both individuals and institutions. Even when internal control procedures are in place, malicious codes from intruders into the network have left so much to be desired. As a result, many Chief Information Security Officers have grown grey hair because of their inability to effectively handle attacks from various ends. Various attempts and technologies have been made in the time past with a measure of success. Intrusion Detection Software (IDS), Intrusion Prevention Software, firewall, honey pots and honey nets have been deployed and with great respite from losses arising from cyber-attacks. Cyber security is the duty of everyone and all must see it as such. As tiers of government and law enforcement agents are doing their best, everybody must be seen to play their parts. Fraudsters have also not seemed to be tired of seeking vulnerabilities to exploit. Then, cyber security experts should not let off their guards but make efforts to harden their security. A way of doing is to intelligently provide a solution that has the capability of detecting and proactively hardening security. This paper proposes a honey net model that is captcha-based and capable of extracting details from hackers with a view to building a robust defense against black hat attackers. This research was able to prevent the botnet with the use of captcha and also redirect suspected traffic to the honeynet which was then captured for the purpose of improving the security of the network. The result showed that any bandwidth greater than the set threshold was not allowed to go into the network but redirected to honeynet where details were logged. Also, with a threshold of 100 mbs, inbound traffic of higher bandwidth such as 110 mbs and 150 mbs was denied access thereby giving 100% detection rate.

Cassava Groundnut Intercropping: A Sustainable Land Management Practice for Increasing Crop Productivity and Organic Carbon Stock on Smallholder Farms

Cassava-groundnut intercropping is not a common practice among smallholder farmers in Sierra Leone even though both crops are well suited for intercropping. On-farm trials were conducted in three locations (Bai Largor, Bassah, and Njala Kanima) in the Moyamba district during the 2021 cropping season to investigate the efficacy of cassava-groundnut intercropping for increasing crop productivity and soil organic carbon stock on smallholder farms in the Moyamba district, Southern Sierra Leone. The experimental design was a randomized complete block design in three replications with treatments of sole groundnut, sole cassava and cassava-groundnut intercropping. Data on the yield and yield components of cassava and groundnut were analysed using the PROC MIXED procedure of SAS 9.4 and means were compared using the standard error of difference (SED). The above-ground biomass, number of roots per plant, and fresh root yield of cassava were not significantly (p > 0.05) affected by the cassava-based cropping system. Averaged across locations, intercropping cassava with groundnut decreased the above-ground biomass, the number of roots per plant, and fresh root yield of cassava by 17%, 11%, and 17%, respectively. The above-ground biomass, number of pods per plant and fresh pod yield of groundnut were significantly (p 1), the highest net revenue and benefit-cost ratio. The benefit-cost ratio was also favourable for the sole cassava (BCR > 1) but not favourable for the sole groundnut (BCR < 1). Averaged across locations, intercropping cassava with groundnut increased the benefit-cost ratio by 121% and 13% when compared to the sole groundnut and sole cassava. In the event of a 40% yield loss for the cassava and groundnut, the benefit-cost ratio was favourable (1.12) only for the cassava groundnut intercropping system. The net soil organic carbon stock was favourable only for the cassava-groundnut intercrop. Averaged across locations, the net soil organic carbon for the cassava-groundnut intercropping increased by 3.4% when compared to the baseline within one cropping cycle of the cassava (12 months). The results confirm that cassava-groundnut intercropping is a sustainable land management practice that could enhance crop productivity and soil organic carbon stock on smallholder farms.

Genetic Screening of Halothane Gene on Selected Philippine Native Pig Herds

The establishment of nucleus herds (NHs) of Native Pigs (NPs) at various R&D stations in the Philippines is currently being undertaken for food security and genetic conservation advocacy. Marker-assisted selection (MAS) is being utilized to identify individuals carrying favorable alleles of genes associated with production traits and screen out genetic defects (GD) for breeding purposes. Porcine Stress Syndrome (PSS) caused by a mutation in Halothane (HAL) gene is a GD frequently found in commercial breeds that when expressed, causes pale, soft, exudative (PSE) meat. PSE is inferior quality meat undesirable in the market causing economic losses to the swine industry. Thus, this study was conducted to screen the HAL gene through mutagenically separated-polymerase chain reaction (MSPCR) in selected NP herds and assessed its repeatability in local breeds. Results showed that out of 577 screened individuals, 543 (94.11%) were normal (NN), 0 (0%) were homozygous mutant (nn) and 34 (5.89%) were heterozygous carriers (Nn). Therefore, the optimized PSS screening protocol using MSPCR is also applicable to local breeds. As such, the availability of genetic tests for PSS could be useful in improving the Philippine NPs breeding selection and inhibiting or eliminating PSS mutant incidence within its nucleus herd.

Quantitative Easing: Money Supply and Commodity Prices of Oil, Gold, and Cocoa in Ghana

This study investigates the dynamic relationships between the money supply (M2) and key commodity prices (Cocoa, Gold, and Crude) in the context of Ghana. Utilizing Vector Error Correction Model (VECM) analysis, we analyze the short-term and long-term Granger causality relationships among these variables, aiming to shed light on the potential linkages between monetary policy and commodity markets. The analysis covers the period from December 1999 to April 2023, using lag structures of 1 and 8 to capture both short-term and more enduring effects. Our findings reveal significant Granger causality relationships between the money supply and various commodities, with nuanced patterns emerging across different lags. In the short-run, our results suggest bidirectional causal relationships between COCOA and M2, CRUDE and M2, and GOLD and M2. Additionally, M2 Granger causes changes in COCOA, CRUDE, and GOLD. However, the causal relationship between COCOA and GOLD appears to be unidirectional, with COCOA not significantly Granger causing changes in GOLD. The short-term findings highlight the intricate interplay between monetary policy and commodity markets. In the long-run (lag 8), our analysis unveils robust Granger causality relationships between the variables. Past values of COCOA, CRUDE, and GOLD Granger cause changes in M2, indicating a notable influence of commodity markets on the money supply. Similarly, M2 Granger causes changes in CRUDE and GOLD. Notably, the findings underscore a more comprehensive and intertwined relationship between monetary policy and commodity prices in the long-run. Based on these results, we derive several policy implications. Policymakers should carefully consider the potential impact of monetary policy decisions, such as quantitative easing, on commodity markets and price dynamics. Measures to stabilize commodity prices, promote export diversification, manage inflation expectations, and enhance economic resilience are recommended. Additionally, effective data monitoring, international collaboration, and proactive risk management strategies are essential components for navigating the complex interactions between monetary policy and commodity markets. This study contributes to a deeper understanding of the intricate connections between monetary policy and commodity prices in Ghana, offering insights for policymakers, researchers, and stakeholders seeking to promote sustainable economic growth and stability. Further research can delve into the mechanisms underlying these relationships and explore their broader implications for trade balances, economic performance, and policy formulation.

Spatiotemporal Analysis of Land Use Land Cover Mapping and Change Detection in Dambatta Local Government Area

This research studied the spatiotemporal changes in land use(LU)/land cover(LC)in Dambatta local government area,with a view to identifying the effect arising from the observable changes in land use patterns.The imageries used in the study were obtained from the National Space Research and Development Agency(NARSDA),Abuja.Spatial analytical techniques and descriptive statistical techniques were employed to analyze the data.The results showed 66.8%reduction in agricultural lands,45.5%reduction in vegetation cover,223.2%increase in built-up areas,269.1%increase in bare lands and 70%increase in water bodies within the 20 years.Spatio-temporal analysis of the three imageries revealed that agricultural lands were largely been taken over by urbanization while vegetation had rapidly given way to bare lands within the 20 years.It was observed that these changes resulted from anthropogenic activities,environmental factors and climate change.These result in the loss of farmlands,inadequate food supply,unemployment,inadequate industrial raw materials,reduction in revenue generated,forest depletion,desertification,wildlife extinction and temperature increase.While it is recommended that reforestation,land reclamation and irrigation agriculture should be promoted in the area,it is also suggested that further research should focus on the impact of climate change on land cover change in the area.

The Evaluation of Alternative Risk Control Schemes Based on Cumulative Prospect Theory

Based on the analysis of the evaluation problems associated with the risk control scheme for major engineering projects,the evaluation method of the risk control scheme considering the irrational behavior of evaluation members in fuzzy random environment is proposed.Firstly,a maximum entropy model corresponding to any evaluation member is es-tablished by using triangular fuzzy random variables and grey correlation coefficient in order to obtain the weight of each risk factor of the member.Secondly,a nonlinear programming model is established according to the principle of minimiz-ing deviation to estimate the weight of different evaluation members on the evaluation of alternative risk control schemes.Lastly,the cumulative entropy model is used to calculate the weight of risk control schemes.Cumulative prospect theory obtains the comprehensive prospect utility value of each alternative to determine the optimal alternative.

速度的三元介质模型

在探井岩心分析与测井解释资料基础上,结合波速机理分析,提出砂泥质岩波速的二级近似式;并将时间平均方程由二元推广到三元,可同时求取砂质岩的泥质分量和孔隙率。文中给出了在塔里木盆地储层研究中的应用实例。

Comparison Between Radial Basis Function Neural Network and Regression Model for Estimation of Rice Biophysical Parameters Using Remote Sensing

The radial basis function (RBF) emerged as a variant of artificial neural network. Generalized regression neural network (GRNN) is one type of RBF, and its principal advantages are that it can quickly learn and rapidly converge to the optimal regression surface with large number of data sets. Hyperspectral reffectance (350 to 2500 nm) data were recorded at two different rice sites in two experiment fields with two cultivars, three nitrogen treatments and one plant density (45 plants m-2). Stepwise multivariable regression model (SMR) and RBF were used to compare their predictability for the leaf area index (LAI) and green leaf chlorophyll density (GLCD) of rice based on reffectance (R) and its three different transformations, the first derivative reffectance (D1), the second derivative reffectance (D2) and the log-transformed re?ectance (LOG). GRNN based on D1 was the best model for the prediction of rice LAI and GLCD. The relationships between different transformations of reffectance and rice parameters could be further improved when RBF was employed. Owing to its strong capacity for nonlinear mapping and good robustness, GRNN could maximize the sensitivity to chlorophyll content using D1. It is concluded that RBF may provide a useful exploratory and predictive tool for the estimation of rice biophysical parameters.

Earthquake swarms near eastern Himalayan Syntaxis along Jiali Fault in Tibet:A seismotectonic appraisal

The seismotectonic characteristics of ten repeated earthquake swarm sequence within a seismic cluster along Jiali Fault in eastern Himalayan Syntaxis(EHS) have been analysed.The swarms are spatially disposed in and around Yigong Lake(a natural lake formed by blocking of Yigong River by landslide) and are characterized by low magnitude,crustal events with low to moderate b values.Ms:mb discriminant functions though indicate anomalous nature of the earthquakes within swarm but are considered as natural events that occurred under condition of high apparent stress and stress gradients.Composite fault plane solutions of selected swarms indicate strike-slip sense of shear on fault planes;solution parameters show low plunging compression and tensional axes along NW-SE and NE-SW respectively with causative fault plane oriented ENE-WSW.dipping steeply towards south or north.The fault plane is in excellent agreement with the disposition and tectonic movement registered by right lateral Jiali Fault.The process of pore pressure perturbation and resultant 'r—t plot' with modelled diffusivity(D = 0.12 m^2/s) relates the diffusion of pore pressure to seismic sequence in a fractured poro-elastic fluid saturated medium at average crustal depth of 15-20 km.The low diffusivity depicts a highly fractured interconnected medium that is generated due to high stress activity near the eastern syntaxial bent of Himalaya.It is proposed that hydro fracturing with respect to periodic pore pressure variations is responsible for generation of swarms in the region.The fluid pressure generated due to shearing and infiltrations of surface water within dilated seismogenic fault(Jiali Fault) are causative factors.

Yangshan Gold Deposit:The Largest Carlin and Carlin-like Type Gold Deposit in China

Gold Headquarter of the CAPF has discovered the Yangshan super large-scale gold deposit in Gansu Province,which is a great breakthrough of gold exploration and prospecting in Western Qiniing Mountains of China.The gold resources of this deposit achieved 308 tons with increasing potentials.Preliminary geological investigations indicate that the Yangshan gold deposit is located in the intra-continental collision orogenic belt;and the deposit was formed during the continent-continent collision orogenic processes.The geological characteristics of the deposit are similar to that of the typical Carlin-type gold deposits,while differences still exist.The ore-forming background is notably different from the Carlin gold deposit province in the United States;and the ore-forming fluids are similar with that of the orogenic-type gold deposit.Accordingly,the Yangshan gold deposit is a transitional type between the Carlin-type and the orogenic type gold deposits.At present,the Yangshan gold deposit is the largest Carlin and Carlin-like type gold deposit that is ever discovered in China. Researches on metallogeny,metallogenic model and ore-enrichment regularities of the Yangshan gold deposit are crucial to meet the pressing needs of the current geological investigation and ore exploration of the deposit.

Detrital K-feldspar^(40)Ar/^(39)Ar Ages:Source Constraints of the Lower Miocene Sandstones in the Pearl River Mouth Basin,South China Sea

The South China Sea began to outspread in the Oligocene.A great quantity of terraneous detritus was deposited in the northern continental shelf of the sea,mostly in Pearl River Mouth Basin,which constituted the main paleo-Pearl River Delta.The delta developed for a long geological time and formed a superimposed area.Almost all the oil and gas fields of detrital rock reservoir distribute in this delta.Thirty-three oil sandstone core samples in the Zhujiang Formation,lower Miocene(23-16 Ma),were collected from nine wells.The illite samples with detrital K feldspar(Kfs) separated from these sandstone cores in four sub-structural belts were analysed by the high-precision 40Ar/39Ar laser stepwise heating technique.All 33 illite 40Ar/39Ar data consistently yielded gradually rising age spectra at the low-temperature steps until reaching age plateaus at mid-high temperature steps.The youngest ages corresponding to the beginning steps were interpreted as the hydrocarbon accumulation ages and the plateau ages in mid-high temperature steps as the contributions of the detrital feldspar representing the ages of the granitic parent rocks in the provenances.The ages of the detrital feldspar from the Zhujiang Formation in the four sub-structural belts were different:(1) the late Cretaceous ages in the Lufeng 13 fault structural belt;(2) the late Cretaceous and early Cretaceous-Jurassic ages in the Huizhou 21 buried hill-fault belt;(3) the Jurassic and Triassic ages in the Xijiang 24 buried hill-fault belt;and(4) the early Cretaceous-late Jurassic ages in the Panyu 4 oil area.These detrital feldspar 40Ar/39Ar ages become younger and younger from west to east,corresponding to the age distribution of the granites in the adjacent Guangdong Province,Southern China.

Identification of the lower limit of high-quality source rocks and its relation to hydrocarbon accumulation——Taking the Beier Sag in the Hailaer Basin as an example

The theory of "source rock control" has evolved from source-rock-control hydrocarbon accumulation, to effective source-rock-control hydrocarbon accumulation, and to high-quality source-rock-control hydrocarbon accumulation. However, there are problems, such as whether high-quality source rocks exist or not? What high-quality source rocks are, and how to identify them, are yet to be agreed upon. Aimed at this issue of concern to explorationists, and taking the Beier Sag in the Hailaer Basin as an example, this paper defines the high-quality source rocks and the lower limit for evaluation of high-quality source rocks, by using the inflection point on the relationship curve of hydrocarbon (oil) expulsion, which is calculated by the material balance principle, versus total organic carbon (TOC). The results show that when TOC is low, all source rocks have limited hydrocarbon expulsion and slow growth rate, thus they cannot be high-quality source rocks. However, when TOC rises to some threshold, hydrocarbon expulsion increases significantly with TOC. This inflection point should be the lower limit of high-quality source rocks: those with TOC greater than the inflection-point value are high-quality source rocks. In addition, the lower limit of high-quality source rocks is also related to the type and maturity of organic matters in the source rocks, as well as the mineral components of the source rocks affecting the residual hydrocarbons. Theoretically, the lower limit of high-quality source rocks depends on geological conditions rather than being a constant value. However, for the sake of simplicity and practicability, in this paper TOC=2.0% is regarded as the lower limit of high-quality source rocks. The examination of such standard in the work area indicates that the high-quality source rocks in members K 1 n 2 and K 1 n 1 of the Nantun formation contribute 76% and 82% to oil generation, and 96% and 91% to oil expulsion , respectively. The distribution of high-quality source rocks is also closely related to the distribution of hydrocarbon reservoirs in the region, demonstrating that high-quality source rocks control hydrocarbon accumulation.

Puziwan Gold Deposit in Shanxi,China:A Special Linear Cryptoexplosive Breccia Type Gold Deposit

The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic. belt of the most famous Au-Ag polymetallic metallogenic belt along the north margin of the North China platform. The secondary metallogenic belt is a synmagmatic tension-shear fault-fracture belt of ENE linear trend. The Indosinian cryptoexplosive breccia body, quartz monzonitic porphyry (beschtauite breccia), quartz monzonite (243.7 Ma, K-Ar), Yanshanian granite-porphyry (105±6 Ma, Rb-Sr) and orebodies mostly occur as dykes or veins and short lenses along the structural fracture belt. The orebodies are emplaced in the fractured cryptoexplosive breccia body in the tectonomagmatic belt and their attitude is consistent with that of the breccia body. The orebodies have two types: one is shallow-seated thick and big ones, which are short-lenticular in plan and wedge-shaped in cross section, shallow buried, large in size

5m宽厚板试样处理自动化系统

随着工业控制技术的不断发展,高性能的PLC在工业控制领域用得越来越广泛,5m宽厚板试样处理自动化系统,运用一个完整的工业控制系统,包括PCS7、编程工程师站、WinCC、HMI画面、PDA跟踪系统、ITV工业监视电视,并结合现场调试经验,对试样处理自动化系统工业控制的系统设计、自动化编程、联动测试、现场调试等进行了描述。

Investigation of the effect of military stress on the prevalence of functional bowel disorders

AIM: To investigate the morbidity of functional bowel disorders (FBD) under military stress conditions in order to lay foundations for the prevention and treatment of this disease. METHODS: Four hundred and fifty-seven soldiers who were assigned to specified services and 471 soldiers who were assigned to routine services were enrolled using cluster sampling, with the latter as a control group. They were surveyed using the Rome Ⅲ FBD standard questionnaire. The FBD symptom question-naire included FBD-related symptoms, severity, dura- tion or attack time, and accompanying symptoms. RESULTS: The morbidity of the military stress group (14.6%) was significantly higher than in the control group (9.98%) ( 2 = 4.585, P < 0.05). The incidence of smoking, abdominal pain and acid regurgitation ( 2 = 4.761, P < 0.05) as well as the ZUNG anxiety/depression scores ( 2 = 7.982, P < 0.01) were also sig- nificantly higher in the military stress group compared with the control group. ZUNG anxiety ( 2 = 11.523, P < 0.01) and depression ( 2 = 5.149, P < 0.05) scores were higher in the FBD group compared with the non-FBD group. The differences in the ZUNG self-rated anxiety and depression scales between the 2 groups were statistically significant ( 2 = 14.482, P < 0.01 and 2 = 6.176, P < 0.05). CONCLUSION: The morbidity of FBD was higher under military stress conditions.

Double linear strain distribution assumption of RC beam strengthened with external-bonded or near-surface mounted fiber reinforced plastic

Rehabilitation of existing structures with fiber reinforced plastic(FRP)has been growing in popularity because they offer superior performance in terms of resistance to corrosion and high specific stiffness.The strain coordination results of 34 reinforced concrete beams(four groups)strengthened with different methods were presented including external-bonded or near-surface mounted glass or carbon FRP or helical rib bar in order to study the strain coordination of the strengthening materials and steel rebar of RC beam.Because there is relative slipping between concrete and strengthening materials(SM),the strain of SM and steel rebar of RC beam satisfies the double linear strain distribution assumption,that is,the strain of longitudinal fiber parallel to the neutral axis of plated beam within the scope of effective height(h0)of the cross section is in direct proportion to the distance from the fiber to the neutral axis.The strain of SM and steel rebar satisfies the equation εGCH=βεsteel,where the value of β is equal to 1.1-1.3 according to the test results.

Comprehensive security risk factor identification for small reservoirs with heterogeneous data based on grey relational analysis model

Identification of security risk factors for small reservoirs is the basis for implementation of early warning systems.The manner of identification of the factors for small reservoirs is of practical significance when data are incomplete.The existing grey relational models have some disadvantages in measuring the correlation between categorical data sequences.To this end,this paper introduces a new grey relational model to analyze heterogeneous data.In this study,a set of security risk factors for small reservoirs was first constructed based on theoretical analysis,and heterogeneous data of these factors were recorded as sequences.The sequences were regarded as random variables,and the information entropy and conditional entropy between sequences were measured to analyze the relational degree between risk factors.Then,a new grey relational analysis model for heterogeneous data was constructed,and a comprehensive security risk factor identification method was developed.A case study of small reservoirs in Guangxi Zhuang Autonomous Region in China shows that the model constructed in this study is applicable to security risk factor identification for small reservoirs with heterogeneous and sparse data.