Web GIS-Based Temporal Analysis of Climatic Factors Impacting Heat Stroke in Karachi

This study focuses on the impact of climate change, specifically the increasing threat of heatwaves, in Pakistan, with a particular emphasis on the city of Karachi. The Pakistan Meteorological Department (PMD) analysed a century of climatic data to reveal warming trends, attributing them to human-induced factors. The vulnerability of Pakistan to climate change is highlighted, given its warm climate and location in a region where temperature increases are expected to surpass global averages. The study examines the past three decades, noting a significant rise in the frequency of hot days, especially in Karachi, where heatwaves have become more prevalent. The aims and objectives of the study involve identifying temporal changes in temperature, rainfall, humidity, and wind speed from 1984 to 2014 in Karachi. The literature review emphasizes the health implications of heatwaves, citing increased mortality during such events globally. The study incorporates a comprehensive temporal analysis, addressing gaps in previous research by considering multiple climate indicators responsible for heatwaves. The methodology involves statistical analyses, including linear regression and Pearson correlation, applied to temperature data and urbanization parameters. Results indicate an increasing trend in heat index temperature, with heatwave vulnerability peaking in the last three decades. Heat Index Temperature Anomalies show a clear surge, emphasizing the need for new indices to control critical heat stress conditions. The study concludes that tropical climate variability, particularly heat index, is linked to extreme hot days, urging measures to reduce population vulnerability. The findings underscore the importance of policy strategies, such as integrated coastal zone management, to mitigate the adverse health effects of heatwaves in Karachi’s vulnerable population.

Determination of Latent Heats of Vaporization and Fusion

Water is the most abundant liquid on the surface of the earth. It is a liquid whose properties are quite surprising, both as a pure liquid and as a solvent. Water is a very cohesive liquid: its melting and vaporization temperatures are very high for a liquid that is neither ionic nor metallic, and whose molar mass is low. Thus, water remains liquid at atmospheric pressure up to 100C while similar molecules such as H2S, H2Se, H2Te for example would give a vaporization temperature close to 80C. This cohesion is in fact ensured by hydrogen bonds between water molecules. This type of bonds between neighboring molecules, hydrogen bonds, is quite often found in chemistry [1] [2]. Any change in the state of aggregation of a substance occurs with the absorption or release of a certain amount of latent heat of transformation. Latent heat of fusion, vaporization or sublimation is the ratio of the energy supplied as heat to the mass of the substance that is melted, vaporized or sublimated. As a result of the reversibility of the processes, the fusion heat is equal to the heat released in the reverse process: crystallization and solidification heat. And likewise the heat of vaporization is equal to the heat of condensation. This equality of heat is often used to determine experimentally either of these quantities. There are two main measurement methods: 1) Direct measurement using the calorimeter, 2) Indirect measure based on the use of the VantHoff relationship. The objective of this work is to measure the latent heat of water vaporization and verify the compatibility of the experimental values with the values given by the tables using the indirect method.

Impact of Dietary Lactobacillus plantarum Postbiotics on the Performance of Layer Hens under Heat Stress Conditions

This experiment was conducted to determine the performance of heat-stressed layers fed a diet containing the probiotic Lactobacillus plantarum RS5 or its products of fermentation (postbiotics). Twenty-week-old Isa White layers, were subdivided into six treatments of 32 individually caged birds. Half of the birds were reared under regular temperature conditions, while the other half was subjected to cyclic daily heat stress. Layers were offered one of three diets: 1) Control;2) Control + Lactobacillus plantarum RS5 probiotic;3) Control + Lactobacillus plantarum RS5 postbiotics. Birds were tested for performance and visceral organ development for 5 months. Heat stress negatively affected the birds’ feed intake, egg weight, shell weight percentage, Haugh unit, shell thickness, yolk color, body weight and spleen weight percentage. Postbiotics significantly increased egg production (p < 0.05) in comparison to the control and the probiotic fed group (94.8% vs 92.6% vs 93.1%, respectively). Birds under probiotic or postbiotic diet showed a significantly higher (p < 0.05) feed intake and egg weight, although the probiotic had a more pronounced and gradual effect. Specific gravity, yolk weight percentage and shell thickness didn’t show differences among dietary groups. The Haugh Unit was significantly higher (p < 0.05) in probiotic group which also showed a significantly lower yolk color index (p < 0.05). The different feed treatments did not impact the bird’s viscera weight percentage, except for the ileum that was significantly lower (p < 0.05) under postbiotic supplementation. Both probiotics and postbiotics could be used as a potential growth promoters and might alleviate heat stress impact in poultry industry.

Mathematical Modelling and Design of Helical Coil Heat Exchanger for Production of Hot Air for Fluidized Bed Dryer

In global industrialization, efforts have been made to increase the rate of heat transfer in heat exchanger, minimizing the size of heat exchanger to reduce cost as well as increasing the effectiveness. Helical coil heat exchanger (HCHE) has been proven to be effective in improving heat transfer due to its large surface area. In this study, HCHE was designed to provide hot air needed for fluidized bed drying processes. The HCHE design model was fabricated and evaluated to study the efficiency of the hot air output for a laboratory fluidized bed dryer. The mathematical model for estimation of the final (output) temperature of air, Taf, passing through the HCHE was developed and validated experimentally. The drying of bitter kola particulates was carried out with a drying temperature of 50C 3C and a bed height-to-bed diameter ratio (H/D) of 1.5. The time taken to dry bitter kola particulates to 0.4% moisture content was 1 hour 45 minutes. Hence, HCHE is recommended for use in the production of hot for laboratory-scale fluidized bed dryers.

Increasing the Efficiency and Level of Environmental Safety of Pro-Environmental City Heat Supply Technologies by Low Power Nuclear Plants

In connection with the current prospect of decarbonization of coal energy through the use of small nuclear power plants (SNPPs) at existing TPPs as heat sources for heat supply to municipal heating networks, there is a technological need to improve heat supply schemes to increase their environmental friendliness and efficiency. The paper proves the feasibility of using the heat-feeding mode of ASHPs for urban heat supply by heating the network water with steam taken from the turbine. The ratio of electric and thermal power of a “nuclear” combined heat and power plant is given. The advantage of using a heat pump, which provides twice as much electrical power with the same heat output, is established. Taking into account that heat in these modes is supplied with different potential, the energy efficiency was used to compare these options. To increase the heat supply capacity, a scheme with the use of a high-pressure heater in the backpressure mode and with the heating of network water with hot steam was proposed. Heat supply from ASHPs is efficient and environmentally friendly even in the case of significant remoteness of heat consumers.

Variational Approach to Heat Conduction Modeling

It is known that Fourier’s heat equation, which is parabolic, implies an infinite velocity propagation, or, in other words, that the mechanism of heat conduction is established instantaneously under all conditions. This is unacceptable on physical grounds in spite of the fact that Fourier’s law agrees well with experiment. However, discrepancies are likely to occur when extremely short distances or extremely short time intervals are considered, as they must in some modern problems of aero-thermodynamics. Cattaneo and independently Vernotte proved that such process can be described by Heaviside’s telegraph equation. This paper shows that this fact can be derived using calculus of variations, by application of the Euler-Lagrange equation. So, we proved that the equation of heat conduction with finite velocity propagation of the thermal disturbance can be obtained as a solution to one variational problem.

Variational Approach to 2D and 3D Heat Conduction Modeling

The paper proposes an approximate solution to the classical (parabolic) multidimensional 2D and 3D heat conduction equation for a 5 × 5 cm aluminium plate and a 5 × 5 × 5 cm aluminum cube. An approximate solution of the generalized (hyperbolic) 2D and 3D equation for the considered plate and cube is also proposed. Approximate solutions were obtained by applying calculus of variations and Euler-Lagrange equations. In order to verify the correctness of the proposed approximate solutions, they were compared with the exact solutions of parabolic and hyperbolic equations. The paper also presents the research on the influence of time parameters τ as well as the relaxation times τ ∗ to the variation of the profile of the temperature field for the considered aluminum plate and cube.

Impact of Cattaneo-Christov Heat Flux in the Nanofluid Flow over an Inclined Permeable Surface with Irreversibility Analysis

This study discusses the magnetohydrodynamic nanofluid flow over an inclined permeable surface influenced by mixed convection, and Cattaeo-Christov heat flux. The heat transfer analysis is performed in the presence of a heat source/sink and thermal stratification. To gauge the energy loss during the process, an irreversibility analysis is also performed. A numerical solution to the envisaged problem is obtained using the bvp4c package of MATLAB. Graphs are drawn to assess the consequences of the arising parameters against the associated profiles. The results show that an augmentation in the magnetic field and nanomaterial volume fraction results in an enhancement in the temperature profile. A strong magnetic field can significantly reduce the fluid velocity. The behavior of the Skin friction coefficient against the different estimates of emerging parameters is discussed. .

Prediction of Low Heating Value of Sugar Cane Bagasse as a Fuel for Industrial Boilers in the High Relative Humidity Region: Case of Cameroon

Many attempts have been made to estimate calorific value of bagasse using mathematical equations, which were created based on data from proximate, ultimate, physical and chemical analysis. Questions have been raised on the applicability of these equations in different parts of the globe. This study was initiated to tackle these problems and also check the most suited mathematical models for the Law Heating Value of Cameroonian bagasse. Data and bagasse samples were collected at the Cameroonian sugarcane factory. The effects of cane variety, age of harvesting, source, moisture content, and sucrose on the LHV of Cameroon bagasse have been tested. It was shown that humidity does not change within a variety, but changes from the dry season to the rainy season;the sugar in the rainy season is significantly different from that collected in the dry season. Samples of the same variety have identical LHV. LHV in the dry season is significantly different from LHV in the rainy season. According to the fact that this study was done for cane with different ages of harvesting, the maturity of Cameroonian sugarcane does not affect LHV of bagasse. Tree selected models are much superior tool for the prediction of the LHV for bagasse in Cameroon compared to others. The standard deviation of these validated models is around 200 kJ/kg compared to the experimental. Thus, the models determined in foreign countries, are not necessarily applicable in predicting the LHV of bagasse in other countries with the same accuracy as that in their native country. There was linear relationship between humidity, ash and sugar content in the bagasse. It is possible to build models based on data from physical composition of bagasse using regression analysis.

A Full Predictor-Corrector Finite Element Method for the One-Dimensional Heat Equation with Time-Dependent Singularities

The energy norm convergence rate of the finite element solution of the heat equation is reduced by the time-regularity of the exact solution. This paper presents an adaptive finite element treatment of time-dependent singularities on the one-dimensional heat equation. The method is based on a Fourier decomposition of the solution and an extraction formula of the coefficients of the singularities coupled with a predictor-corrector algorithm. The method recovers the optimal convergence rate of the finite element method on a quasi-uniform mesh refinement. Numerical results are carried out to show the efficiency of the method.

Heat and Mass Transfer for a Nanofluid Flow in Fluidized Bed Dryer in Presence of Induced Magnetic Field

This research entails the study of heat and mass transfer of nanofluid flow in a fluidized bed dryer used in tea drying processes in presence of induced magnetic field. A mathematical model describing the fluid flow in a Fluidized bed dryer was developed using the nonlinear partial differential equations. Due to their non-linearity, the equations were solved numerically by use of the finite difference method. The effects of physical flow parameters on velocity, temperature, concentration and magnetic induction profiles were studied and results were presented graphically. From the mathematical analysis, it was deduced that addition of silver nanoparticles into the fluid flow enhanced velocity and temperature profiles. This led to improved heat transfer in the fluidized bed dryer, hence amplifying the tea drying process. Furthermore, it was noted that induced magnetic field tends to decrease the fluid velocity, which results in uniform distribution of heat leading to efficient heat transfer between the tea particles and the fluid, thus improving the drying process. The research findings provide information to industries on ways to optimize thermal performance of fluidized bed dryers.

Sterilization Effect of Cooking Process for Guilin Rice Noodles Based on Heat Conduction Model

Guilin rice noodles, a unique cuisine from Guilin, Guangxi, is renowned both domestically and internationally as one of the top ten “Guilin Classics”. Utilizing a heat conduction model, this study explores the effectiveness of the cooking process in sterilizing Guilin rice noodles before consumption. The model assumes that a large pot is filled with boiling water which is maintained at a constant high temperature heat resource through continuous gentle heating. And the room temperature is set as the initial temperature for the preheating process and the final temperature for the cooling process. The objective is to assess whether the cooking process achieves satisfactory sterilization results. The temperature distribution function of rice noodle with time is analytically obtained using the separation of variables method in the three-dimensional cylindrical coordinate system. Meanwhile, the thermal diffusion coefficient of Guilin rice noodles is obtained in terms of Riedel’ theory. By analyzing the elimination characteristics of Pseudomonas cocovenenans subsp. farinofermentans, this study obtains the optimal time required for effective sterilization at the core of Guilin rice noodles. The results show that the potential Pseudomonas cocovenenans subsp. farinofermentans will be completely eliminated through continuously preheating more than 31 seconds during the cooking process before consumption. This study provides a valuable reference of food safety standards in the cooking process of Guilin rice noodles, particularly in ensuring the complete inactivation of potentially harmful strains such as Pseudomonas cocovenenans subsp. farinofermentans.

Finite-Time Thermodynamic Simulation of Circulating Direct Condensation Heat Recovery on Chillers

A time series model is used in this paper to describe the progress of circulating direct condensation heat recovery of the compound condensing process (CCP) which is made of two water cooling condensing processes in series for a centrifugal chiller in the paper. A finite-time thermodynamics method is used to set up the time series simulation model. As a result, an upper bound of recoverable condensation heat for the compound condensing process is obtained which is in good agreement with experimental result. And the result is valuable and useful to optimization design of condensing heat recovery.

Geospatial Analysis of Urban Heat Island Effects and Tree Equity

In recent decades, Urban Heat Island Effects have become more pronounced and more widely examined. Despite great technological advances, our current societies still experience great spatial disparity in urban forest access. Urban Heat Island Effects are measurable phenomenon that are being experienced by the world’s most urbanized areas, including increased summer high temperatures and lower evapotranspiration from having impervious surfaces instead of vegetation and trees. Tree canopy cover is our natural mitigation tool that absorbs sunlight for photosynthesis, protects humans from incoming radiation, and releases cooling moisture into the air. Unfortunately, urban areas typically have low levels of vegetation. Vulnerable urban communities are lower-income areas of inner cities with less access to heat protection like air conditioners. This study uses mean evapotranspiration levels to assess the variability of urban heat island effects across the state of Tennessee. Results show that increased developed land surface cover in Tennessee creates measurable changes in atmospheric evapotranspiration. As a result, the mean evapotranspiration levels in areas with less tree vegetation are significantly lower than the surrounding forested areas. Central areas of urban cities in Tennessee had lower mean evapotranspiration recordings than surrounding areas with less development. This work demonstrates the need for increased tree canopy coverage.

More extreme-heat occurrences related to humidity in China

极端日夜复合高温往往会造成更为严重的社会经济影响及健康风险,受到了广泛关注。本文基于ERA5逐小时资料,针对中国区域极端日夜复合湿热和高温事件的变化及其影响进行了比较分析.结果指出,中国区域夏季极端湿热和高温在空间分布上较为一致,强度高值区主要分布在南方地区,但高频中心主要出现在北方地区.两类事件发生频次在全国范围内均呈明显增加趋势,尤其在西部和北部地区.进一步研究表明,在中国大部分地区,湿度异常在极端湿热事件变化中有着十分重要的作用,部分区域甚至超过温度异常的影响。随着极端湿热事件的增加其影响也在加剧,自1961年以来中国暴露于极端湿热事件的人口数量和城市面积增速明显大于高温事件.

预制烤鱼水分分布及关键挥发性风味物质分析

以即热型预制烤鱼为研究对象,采用低场-核磁共振技术(Low field-nuclear magnetic resonance,LF-NMR)、顶空固相微萃取与气相色谱质谱联用技术(Headspace-solid phase microextraction-gas chromatography mass spectrometry,HS-SPME-GC-MS)对不同电烤条件下烤鱼水分分布及挥发性风味物质进行研究。结果表明:250℃烤制20 min的烤鱼加工损失率最低,持水力最高。烤鱼中水分主要形式为不易流动水,200℃烤鱼的弛豫时间T22、T23最低,其次是250℃烤鱼,T2反演谱整体向左移动,说明水的自由度降低。250℃烤制20 min的烤鱼不易流动水峰面积占比(A22)最高,达94.03%,自由水峰面积占比(A23)最低,为1.93%,说明肌肉组织持水较优。在5组烤鱼中共鉴定出70种挥发性物质,主要为醛类、酮类、醇类及烃类等。通过相对气味活度值(Relative odor activity value,ROAV)筛选出关键挥发性风味物质分别为12、9、11、8和8种。5组样品贡献较大的风味物质为己醛、1-辛烯-3-醇、壬醛等,其中愈创木酚和4-甲基苯酚是碳烤烤鱼特有的关键风味物质。通过主成分分析,不同条件烤制的烤鱼关键挥发性风味物质差异明显。相关性分析表明,A22与异戊醛、庚醛和2,3-辛二酮呈显著正相关(P<0.05),与壬醛和愈创木酚呈显著负相关(P<0.05)。该研究结果为预制烤鱼开发提供参考。

响应面法优化高顺式虾青素的制备工艺研究

天然存在的虾青素多为全反式构型,但顺式构型的虾青素具有更好的生物活性且更易被人体选择性吸收。为研究高顺式虾青素的制备工艺,该实验采用微波加热法对虾青素进行虾青素异构化,以全反式虾青素为原料,乙酸乙酯为溶剂,虾青素顺式占比为评价指标,采用单因素及响应面试验优化了虾青素异构化。得出制备高顺式虾青素最佳条件为:催化剂为异硫氰酸甲酯60 mg/mL,虾青素溶液质量浓度1.5 mg/mL,微波温度69℃,微波功率600 W,微波时间22 min。最佳条件下虾青素总顺式占比为49.34%,该研究有利于提高虾青素顺式比例,为虾青素用于功能性食品打下理论基础。

新型乌蔹莓水凝胶对湿热蕴结型痛风性关节炎的干预效果

目的探讨新型乌蔹莓水凝胶对湿热蕴结型痛风性关节炎的干预效果及作用机制。方法选取90例符合痛风性关节炎西医诊断标准、中医辨证属湿热蕴结证的患者作为研究对象,随机分成治疗组、对照组和空白组,每组30例。空白组仅采用依托考昔治疗,对照组采用依托考昔联合乌蔹莓膏治疗,治疗组采用依托考昔联合外敷乌蔹莓水凝胶治疗。比较3组临床疗效、症状改善时间、安全性、舒适性和治疗前后中医证候积分、血清炎性因子[C反应蛋白(CRP)、肿瘤坏死因子-α(TNF-α)、血沉(ESR)]、NF-κB信号通路相关蛋白、疼痛视觉模拟评分法(VAS)评分、关节活动度变化情况。结果治疗组、对照组治疗总有效率分别为93.33%、90.00%,高于空白组的70.00%,差异有统计学意义(P<0.05);治疗组疼痛、红肿、压痛、关节活动受限症状改善的时间短于对照组、空白组,差异有统计学意义(P<0.05);治疗7 d后,治疗组中医证候积分低于对照组、空白组,治疗组、对照组血清CRP、TNF-α、ESR水平和NF-κB信号通路相关蛋白P50、P65表达低于空白组,差异有统计学意义(P<0.05);治疗组治疗7 d后VAS评分低于对照组、空白组,且治疗组用药舒适度评分高于对照组,差异有统计学意义(P<0.05);3组不良反应发生率比较,差异无统计学意义(P>0.05)。结论乌蔹莓水凝胶对痛风性关节炎的治疗效果优于乌蔹莓膏,其作用机制可能与调控NF-κB通路、抑制炎性因子表达有关,且水凝胶使用方便卫生,舒适性高,有望成为安全、有效、便捷的痛风性关节炎外敷中药。

2023年夏季我国气候异常特征及成因分析

2023年夏季,我国气候特征整体表现为“温高雨少”,区域性、阶段性高温、旱涝等气象灾害明显。降水的空间分布差异显著,主要多雨区位于我国北方,松花江、海河流域出现严重汛情。生成和登陆台风频数均较常年同期偏少,但北上台风却对京津冀等地造成极其严重的雨涝灾害。2023年夏季我国气温为1961年以来历史次高,北方地区暖异常明显,华北、西北等地区阶段性高温热浪尤为突出。华北、东北地区降水偏多是由不同环流系统造成的。其中,华北南部降水异常偏多主要由7月底至8月初一次极为罕见的天气尺度持续性极端降水过程所致,台风杜苏芮和卡努外围环流与异常偏西、偏北的西太平洋副热带高压相配合,再加上太行山东麓的地形效应是其主要原因。盛夏东北东部异常偏南风引导的水汽输送在整个对流层都异常偏强,造成东北北部和东部降水明显偏多,这一异常环流与初夏巴伦支海海冰密集度减小及盛夏西北太平洋海温异常偏暖均有一定关联。

智慧供热系统数据运行核查方法研究

高质量数据是智慧供热系统数据分析的前提和分析结论可靠性的保障,计量器具的良好工作状态是获得高质量数据的基础。本文讨论了计量器具的检定、校准及运行核查的区别,研究了智慧供热系统计量器具在线运行核查方法。研究表明:流量计根据其实际安装工作条件,采用安装条件修正系数可解决直管段长度不够带来的测量误差问题;采用基准表法对使用的流量计进行技术性能核查,可正确判别单台流量计的工作状态;示踪法是解决大口径贸易结算表数据质量问题的有效方法。本研究可为及时发现工作异常的计量器具、确保测量数据的准确性及可靠性提供理论指导及技术支撑。