Operational feasibility study of stagnation pressure reaction control for a mid-caliber non-spinning projectile

Controlled,guided munitions can reduce dispersion in the shot,while providing the capability of engaging both stationary and maneuvering targets.The Netherlands Organisation for Applied Scientific Research has developed a fin-less control technology called Stagnation Pressure Reaction Control(SPRC)that takes stagnation pressure air and directs it sideways to control non-spinning projectiles.In a previous study,this technology was demonstrated at Mach 2 wind-tunnel conditions to achieve up to 1.5°controllable angle of incidence for a non-spinning,aerodynamically unstable projectile-like test object.In an operational scenario,the decelerating projectile will experience a decline in control force while the simultaneous forward shift of the center of pressure increases the need for control force.Furthermore,angles of incidence exceeding 1.5°will be experienced under realistic flight conditions,especially against maneuvering targets.This work addresses these challenges and presents an operational feasibility study for a practical application of SPRC in a non-spinning mid-caliber gun-launched projectile,using experiment data on control latency and force of the earlier study.It illustrates the combined effect of the control-and stability dynamics and underlines the potential of an SPRC projectile as a precisionoperation ammunition.This research revealed that SPRC technology can stabilize and control the hypothesized projectile in a direct fire scenario against stationary and maneuvering targets.

A Feasibility Study of Using Geothermal Energy to Enhance Natural Gas Production from Offshore Gas Hydrate Reservoirs by CO_(2) Swapping

The energy industry faces a significant challenge in extracting natural gas from offshore natural gas hydrate(NGH)reservoirs,primarily due to the low productivity of wells and the high operational costs involved.The present study offers an assessment of the feasibility of utilizing geothermal energy to augment the production of natural gas from offshore gas hydrate reservoirs through the implementation of the methane-CO_(2)swapping technique.The present study expands the research scope of the authors beyond their previous publication,which exclusively examined the generation of methane from marine gas hydrates.Specifically,the current investigation explores the feasibility of utilizing the void spaces created by the extracted methane in the hydrate reservoir for carbon dioxide storage.Analytical models were employed to forecast the heat transfer from a geothermal zone to an NGH reservoir.A study was conducted utilizing data obtained from a reservoir situated in the Shenhu region of the Northern South China Sea.The findings of the model indicate that the implementation of geothermal heating can lead to a substantial enhancement in the productivity of wells located in heated reservoirs during CO_(2)swapping procedures.The non-linear relationship between the temperature of the heated reservoir and the rate of fold increase has been observed.It is anticipated that the fold of increase will surpass 5 when the gas hydrate reservoir undergoes a temperature rise from 6℃ to 16℃.The mathematical models utilized in this study did not incorporate the impact of heat convection resulting from CO_(2)flow into the gas reservoir.This factor has the potential to enhance well productivity.The mathematical models’deviation assumptions may cause over-prediction of well productivity in geothermal-stimulated reservoirs.Additional research is required to examine the impacts of temperature drawdown,heat convection resulting from depressurization,heat-induced gas pressure increment,and the presence of free gas in the formation containing hydrates.The process of CH4-CO_(2)swapping,which has been investigated,involves the utilization of geothermal stimulation.This method is highly encouraging as it enables the efficient injection of CO_(2)into gas hydrate reservoirs,resulting in the permanent sequestration of CO_(2)in a solid state.Additional research is warranted to examine the rate of mass transfer of CO_(2)within reservoirs of gas hydrates.

Lymph node metastasis in early gastric cancer with submucosal invasion:Feasibility of minimally invasive surgery

AIM:To explore the feasibility of pertorming minimally invasive surgery(MIS)on subsets of submucosal gastric cancers that are unlikely to have regional lymph node metastasis. METHODS:A total of 105 patients underwent radical gastrectomy with lymph node dissection for submucosal gastric cancer at our hospital from January 1995 to December 1995.Besides investigating many clinicopathological features such as tumor size,gross appearance,and differentiation, we measured the depth of invasion into submucosa minutely and analyzed the clinicopathologic features of these patients regarding lymph node metastasis. RESULTS:The rate of lymph node metastasis in cases where the depth of invasion was<500 μm,500-2 000 μm,or >2 000 μm was 9%(2/23),19%(7136),and 33%(15/46), respectively(P<0.05).In univariate analysis,no significant correlation was found between lymph node metastasis and clinicopathological characteristics such as age,sex,tumor location,gross appearance,tumor differentiation,Lauren's classification,and lymphatic invasion.In multivariate analysis, tumor size(>4 cm vs≤2 cm,odds ratio=4.80, P=0.04)and depth of invasion(>2 000 μm vs ≤500 μm, odds ratio=6.81,P=0.02)were significantly correlated with lymph node metastasis.Combining the depth and size in cases where the depth of invasion was less than 500 μm, we found that lymph node metastasis occurred where the tumor size was greater than 4 cm.In cases where the tumor size was less than 2 cm,lymph node metastasis was found only where the depth of tumor invasion was more than 2 000 μm. CONCLUSION:MIS can be applied to submucosal gastric cancer that is less than 2 cm in size and 500 μm in depth.

Feasibility study using simulation mode for offshore field SZ36-1

Field SZ36-1 is a water-flooded heavy oil reservoir with high porosity and unconsolidated sand. The recovery rate is low so that it becomes a challenge for production. Time-lapse seismic data is studied to improve the oil recovery for this field, This feasibility study analyzes the possible time-lapse seismic attribute spatial distribution using dynamic data and the reservoir model to determine the optimum time to acquire a new seismic survey. Based on the study, it is found that the time-lapse seismic response for this unconsolidated sand has a strong signature due to solution gas when the reservoir pressure is below the bubble point. This indicates that acquiring a new survey after 10 years of production is appropriate for a time-lapse seismic application.

Application of the Landsat-5TM Image Data in the Feasibility Study of Mudflow Hazards in the Southern Taihang Mountains

The Taihang Mountains area is an area in North China where serious mudflow hazards take place frequently. The hazards often obstrust traffic and make it difficult to carry out conventional ground investigations of the mudflow hazards. This paper introduces the feasibility study of mudflow hazards by using Landsat-5TM data. The study has achieved a great success through adopting both the faint spectral enhancement technique for mudflow fans (or other depositional areas) and comprehensive study of the environmental background of pregnant mudflows. Thus, remote sensing as a fast, convenient, low-cost and effective technical method can be used to recognise the situation of mudflow hazards so that effective rescue can be provided.

Feasibility study of highwall mining in north surface mine of Yima Coal Corporation, China

Yima Coal Corporation is considering to adopt highwall mining method withauger machine to recover coal from north surface pit that has reached final highwall position. Themajor geomechanical issues associated with auger mining are highwall and pillar stability. Based onthe field investigation and laboratory test results of mechanical parameters, numerical modeling iscarried out to assess the stability of highwall and pillar. Field measurements of highwalldeformation have been used to validate and ensure the confidence for the development of realisticmodels. The results of numerical modeling show that the mining method is feasible for mining theseam of 10 m thickness in north surface coal mine.

Feasibility Study on Continuous Mining Method in Deep Position of Jinchuan Nickel Mine, China

Jinchuan nickel mine is the largest nickel mine in China. Cut-and-fill mining method with high density cementing materials is used in the mine. The original mining design divided the mining operation into two steps. The first step stopped the mining rooms and the second step stopped the pillars. Because the two-step method made big trouble for finally mining pillars and strongly limited the mining speed and production, it was successfully changed to a continuous cut-and-fill method without pillars. However, the mining operation in the mine has been down to 800 m and the mining condition is getting worse and more complicated. Through systematical field investigations and 3-D FEM analysis, it is proved that the mining method without pillars is feasible for mining deeper orebodies in Jinchuan nickel mine.

Preliminary Feasibility Study on Application of Very Large Scale-Photovoltaic Power Generation in China

Some energy experts believe that solar energy photovoltaic power generation is hopeful to be applied in a large amount and possesses a certain proportion in the structure of energy in the future. In this paper, based on the forecasting of electric load demand and energy structure of power generation in the middle of 21 century, the pictures of VLS-PV power genera- tion is composed, the operation characteristic of VLS-PV power generation and the adaptability of electric power grid for it is analyzed, the ways for transmitting large amount of PV power and the economic and technical bottlenecks for applying VLS-PV power generation are discussed. Finally, the steps and suggestions for developing VLS-PV power generation and its electric power system in China are proposed.

The Remote Testing in Abbiategrasso (RTA) Study Protocol: A Counter-Balanced Crossover Trial to Assess the Feasibility of Direct-to-Home-Neuropsychology with Older People

Background: The Sars-Cov-2 pandemic has accelerated the spreading of telemedicine, including TeleNeuroPsychology (TNP). Also in a non-pandemic scenario, TNP gives the advantage of reaching older subjects, which often have mobility or transportation limitations. Previous studies on the feasibility, acceptability and reliability of TNP provide promising indications. However, it remains unclear how elderly populations in Italy welcome this practice, in particular when carried out “direct-to-home” (DTH neuropsychology—DTH-NP), hence without assistance in setting up, i.e., the videoconference, and which tests validated in Italian populations show good comparability between remote (either by voice phone call or videoconference) and face-to-face administration. Aims: Here we present a study protocol aimed at assessing: 1) the recruitment rate in a study on DTH neuropsychological assessment through voice calls or videoconference, 2) the feasibility and acceptability of a DTH neuropsychological assessment, 3) the comparability between DTH and face-to-face neuropsychological assessments. Methods: Fifty-eight older adults (65 - 85 years) were recruited among donors of the Abbiategrasso Brain Bank and will undergo both a face-to-face and a DTH neuropsychological assessment in a counterbalanced cross-over design (Group 1: remote session first;Group 2: face-to-face session first). Recruitment rate will be first evaluated. Then, the responses to an acceptability questionnaire will be compared between the two administration modalities. Finally, the DTH-face-to-face comparability will be evaluated as good reliability of a DTH neuropsychological assessment and agreement between scores obtained in the two modalities. Discussion and Conclusion: This study protocol aims at describing the procedures allowing a more reliable implementation of DTH-NP in the Italian clinical and research contexts. The inclusion of both phone-call and videoconference DTH neuropsychological assessment will give the opportunity to evaluate the feasibility of DTH-NP also in older adults with low digital skills. The results of the comparability analysis will offer the first evidence in the Italian context on which neuropsychological tests can be reliably delivered DTH, by phone call or videoconference.

Feasibility Study on Welding Structure of the HT-7U Toroidal Field Coil Case

The Toroidal Field (TF) coil case of the HT-7U superconducting tokamak device is made of austenitic stainless steel 316LN and is designed to operate at cryogenic temperature (4 K). 316LN can retain high strength and fracture toughness at 4 K. Feasibility study on technical process of welding has been experimentally considered as a hopeful joint method for suppression of post-welding deformation and reduction of over-heating. Meanwhile the final range of stress intensity and the stress intensity factor (K) for pre-cracks of welding structure have been determined by using J-integral. These related results are optimistic and have shown that there's no problem in strength and fracture toughness at the vicinity of the pre-crack tip. This paper introduces the welding structure of TF coil case in detail.

Feasibility Study of Installing Rooftop PV System with Net-Metering Scheme in Iraq

Renewable energy, particularly solar energy, offers a clean and alternative energy source to meet the energy demand for sustainable development in the world. Due to its profitability and viability, PV net-metering scheme has been adopted in many countries. The feasibility of implementation PV rooftop system with net metering in residential, commercial, governmental and industrial sectors in Iraq is demonstrated in this study. A financial model has been developed to investigate the feasibility parameters NPV, IRR and annual savings of 24 kWp PV system. The results showed that increasing the capacity of the PV system in residential and commercial buildings will lead to a profitable investment return and the breakeven point that may make the PV net-metering projects feasible is very close to the tariff applied for the commercial sector (10.29 $c/kWh). In the governmental sector, the tariff needs to increase by 35.1% to reach breakeven. However, for such net-metering scheme to be attractive and feasible on a wide scale, it is crucial to back it with financial support through soft loans and grants.

Feasibility Study for Power Generation during Peak Hours with a Hybrid System in a Recycled Paper Mill

The differential pricing for peak hours encourages industrial consumers to look for independent power supplies for the period from 19 to 22 hours. This paper presents a study to identify the optimal solution for a recycled paper mill that also intends to work in that period. The factory is located in Rio Grande do Sul, in southern Brazil, and considers the use of a diesel gen set, a micro hydro power plant and possibly PV modules. Two micro hydro power plants were considered in the study, an old plant to be renewed and another to be fully implemented. The software Homer was used as a tool to determine the most feasible combination of components considered in the study. The sale of surplus power to the energy system appears as a key to viability of alternatives that are not based solely on diesel generators. The optimal solution consists of a combination of diesel generators and micro hydro power plant, in one case, and only on hydroelectric power plant in another, with a significant penetration of PV modules if its cost is reduced to 12% of the current price, selling an amount of energy equal to that which is bought. The annual water availability in one of the sites requires diesel supplement, while the other, more abundant, this supplement is not necessary.

Economic-Technical Feasibility Study of the ＂Sierra de Tineo＂ Wind Farm Expansion. Tineo-Principality of Asturias （Spain）

The aim of this work is double. Firstly, we want to stress out that investing in renewable energies in 2009 in Spain was a profitable activity. This question will be answered studying the possibilities of expanding ＂Sierra de Tineo＂ wind farm in the Principality of Asturias （location, wind resource, data analysis, simulation, legal standards and economic and sensitivity study of the investment）, and for that, data from the year 2009 have been used. And secondly, the goal is to set the bases for a future paper where the current situation of Spain （within the renewable framework）, will be compared with the 2009 scenario.

REVIEW OF THE FEASIBILITY STUDY OF BEIJING TAU-CHARM FACTORY

In the field of large-capacity accelerator construction, there are two world-wide trends now evident in high-energy physicists: one is to build up high-energy ones such as the LHC (Large Hadron Collider) developed by Conseil Européen pour la Recherches Nucleaires (CERN) and the other features high precision, including β-factories in the US and Japan and the φ-factory and τ-factory

PROGRESS IN THE FEASIBILITY STUDY OF THE BEIJING TAU-CHARM FACTORY

The feasibility study of the Beijing Tau-Charm Factory(BTCF), approved by the Chinese government to have been completing from February of 1995 to the end of 1996, has been carried out successfully by the Institute of High-Energy Physics (IHEP) under the CAS.Also this is a cooperative project shared by seven Chinese institutions of Peking University,the CAS Institute of Theoretical Physics,Nanjing University,Shandong University,Shanghai Jiaotong University, Qinghua University and the CAS-affiliated University of S&T of China. The main tasks of this study are:

Development of engineered cementitious composites with local ingredients

In order to reduce the cost of high performance polyvinyl alcohol（PVA） fiber reinforced cementitious material（called engineered cementitious composites,ECC）,a ductile ECC material is developed using domestic PVA fibers along with other local ingredients,such as fly ash,cement and sand.In addition to the economic analysis of ECC,the four-point bending test and the optical microscope are employed to investigate the deflection capacity of ECC,its crack width and the occurrence of the self-healing phenomenon.The experimental results suggest that ECC made with domestic ingredients exhibits larger deformability and the average crack width is controlled around 60 μm.Furthermore,the self-healing behavior is observed in cracks of the specimens after cycles of wet and dry curing.The economic analysis shows that the cost of ECC can be greatly reduced via employing domestic PVA fibers.It is,therefore,feasible to produce low cost ECC material employing domestic PVA fibers,while simultaneously retaining high material ductility.