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Thermal design and analysis of heat exchangers are predominantly conducted considering constant heat transfer coefficients. However, these vary along the length and affect the calculations of heat transfer rates and area allocations. The current paper investigates the variations in the heat transfer coefficients in plate heat exchangers (PHX), using different numerical approaches. The heat transfer coefficient is calculated at the inlet, outlet, and systematically selected intermediate points for each method. The analysis is conducted for two different systems, i.e., a laboratory-scale and an industrial scale PHX at different chevron angles. It is concluded that the effect of the variable heat transfer coefficient is more significant for the large-scale heat exchanger due to high flow rates, geometrical specifications, Reynolds number, and thermophysical properties. The deviation of the local heat transfer coefficient along the heat exchanger length is approximately 9–14% and 3–6% for industrial and laboratory scale PHX, while an area deviation of around 15% is observed.

Russia-Ukraine War has reignited the debate over nuclear deterrence, put non-proliferation gains at stake and may likely to cause implications for tension areas across the globe. This has further shaken security assurances from United States, Nato in asymmetrical tension areas, and perceived outcomes are exhibiting more alarming and scarier picture. Ukraine was promised security in line with the 1992 Lisbon treaty. The treaty ensured that through giving up its nuclear weapons Ukraine will be granted the means through which it can ensure its borders through conventional ways. In addition to this, it was also provided guarantees of security by UK, the USA and Russia, should it ever face a threat by an external force. However, as recent events have come to unfold. It has become obvious that all such promises of security were of no use, that when Russia decided to take up arms against the state of Ukraine there was not much standing between Ukraine and destruction.The paper will examine how this war perpetuates and impacts in other tension areas. States like South Korea and Iran who are being promised security might see this as a case study of why it is pertinent for them to turn to nuclearization. Lastly, we shall also see the case study of South Asian theatre where Pakistan, a financially weaker state chose to develop nuclear weapons irrespective of the promises that the western nations made to deter India through nuclearization. And through these measures it has been successful in maintaining deterrence and a relative balance of power with a much bigger adversary. In the most important sense, the paper explores the impact of power equation on arms race and nonproliferation, and it poses new threats to the power balancing in regions across the globe., Ресей мен Украина арасындағы соғыс ядролық қаруды тежеу ​​жөніндегі пікірталастарды қайта жандандырды, таратпау саласындағы табыстарды қауіп төндірді және дүние жүзіндегі ыстық нүктелерде салдары болуы мүмкін. Бұл асимметриялық шиеленіс аймақтарында Америка Құрама Штаттары мен НАТО-ның қауіпсіздік кепілдігін одан әрі бұзды және күтілетін нәтижелер алаңдатарлық және қорқынышты көріністі көрсетеді. 1992 жылғы Лиссабон келісімі бойынша Украинаға қауіпсіздікті қамтамасыз етуге уәде берілді.Келісім ядролық қарудан бас тарту арқылы Украина өз шекараларын әдеттегідей қамтамасыз ете алатын құралдарды алатынына кепілдік берді. Бұған қоса, Ұлыбритания, АҚШ және Ресей оған сыртқы күштерден қауіп төнген жағдайда қауіпсіздік кепілдігін берді.Дегенмен, соңғы оқиғалардың беті ашылды. Қауіпсіздік туралы мұндай уәделердің бәрі пайдасыз екені, Ресей Украина мемлекетіне қарсы қару алуға шешім қабылдаған кезде Украина мен жойылу арасында көп нәрсе болмағаны белгілі болды.Қағаз бұл соғыстың қалай жалғасатынын және басқа шиеленіс аймақтарына қалай әсер ететінін қарастырады. Қауіпсіздікке уәде етілген Оңтүстік Корея мен Иран сияқты мемлекеттер мұны неліктен ядролық қарулануға бет бұрғанын нақты мысал ретінде қарастыруы мүмкін. Соңында, біз сондай-ақ Батыс елдерінің Үндістанды ядролық қаруландыру арқылы тежеу ​​үшін берген уәделеріне қарамастан, қаржылық жағынан әлсіз мемлекет Пәкістан ядролық қару жасауды таңдаған Оңтүстік Азия театрының жағдайын көреміз. Осы шаралар арқылы ол әлдеқайда үлкен қарсыласпен тежеу ​​және салыстырмалы күш тепе-теңдігін сақтауда сәтті болды. Ең маңызды мағынада, жұмыс күш теңдеуінің қарулану жарысы мен таратпауға әсерін зерттейді және ол бүкіл әлемдегі аймақтардағы қуат теңгеріміне жаңа қауіп төндіреді, Война между Россией и Украиной вновь разожгла дебаты о ядерном сдерживании, поставила на карту достижения в области нераспространения и, вероятно, может привести к последствиям в зонах напряженности по всему миру. Это еще больше поколебало гарантии безопасности со стороны Соединенных Штатов и НАТО в зонах асимметричной напряженности, и предполагаемые результаты демонстрируют более тревожную и пугающую картину. Украине была обещана безопасность в соответствии с Лиссабонским договором 1992 года. Договор гарантировал, что, отказавшись от своего ядерного оружия, Украина получит средства, с помощью которых она сможет обеспечить свои границы обычными способами. В дополнение к этому, Великобритания, США и Россия предоставили ему гарантии безопасности в случае, если он когда-либо столкнется с угрозой со стороны внешней силы.Однако, как только разворачиваются последние события. Стало очевидно, что все эти обещания безопасности бесполезны, что, когда Россия решила взяться за оружие против государства Украина, между Украиной и разрушением не так уж много стояло.В документе будет рассмотрено, как эта война увековечивает и влияет на другие области напряженности. Такие государства, как Южная Корея и Иран, которым обещают безопасность, могут рассматривать это как пример того, почему им уместно обратиться к ядерной политике. Наконец, мы также увидим тематическое исследование театра военных действий в Южной Азии, где Пакистан, более слабое в финансовом отношении государство, решил разработать ядерное оружие вопреки обещаниям, которые западные страны дали для сдерживания Индии посредством ядерной ядерной программы. И с помощью этих мер ему удалось сохранить сдерживание и относительный баланс сил с гораздо более крупным противником. В наиболее важном смысле статья исследует влияние уравнения сил на гонку вооружений и нераспространение, а также ставит новые угрозы балансу сил в регионах по всему миру., Международные отношения и Регионоведение, Выпуск 3 (49) 2022

Exergoeconomic analysis, a simultaneous investigation of exergetic and monetary performance has attained significant attention to analyze and improve the performance of energy conversion systems. This combined analysis allows an individual audit of all the components in the system. The research is particularly useful for multi-component systems to get a better understanding of how effectively each component consumes energy and economic capital. This chapter aims to present a comprehensive theoretical framework for exergoeconomic study of thermal systems. For this purpose, the framework is initially developed for standalone heat exchangers and then extended to commercial-scale thermal desalination systems consisting of preheaters, pumps, evaporators, and compressors, etc. The exergetic and economic values of each stream in the system were evaluated using the developed framework. The sensitivity and parametric analysis of different thermodynamic and economic parameters on the system performance was conducted to study the performance variations. The presented model can be generalized for performance analysis of other systems.

Integration of energy recovery section with thermal desalination systems improves their performance from thermodynamics, economics, and environmental viewpoints. This is because it significantly reduces input energy, heat transfer area, and capital cost requirements. Above all, the system outlet streams can achieve thermal equilibrium with the environment by supplying heat for useful preheating purposes thus reducing the environmental impacts. The plate heat exchangers are generally employed for this purpose as preheaters. The current paper presents a comprehensive investigation and optimization of these heat exchangers for thermal desalination systems applications. An experimentally validated numerical model employing Normalized Sensitivity Analysis and Genetic Algorithm based cost optimization is developed to investigate their performance at assorted operating conditions. The analysis showed that the heat transfer coefficient, pressure drop, and outlet water cost were improved by an increase in feed flow rate. However, with an increased flow rate, the comprehensive output parameter (h/ΔP) decreased due to the high degree increase in pressure drop. Moreover, an increase in the chevron angle reduced the heat transfer coefficient, pressure drop, and water cost. Finally, the optimization lowered the heat transfer area by ~79.5%, capital investment by ~62%, and the outlet cost of the cold stream by ~15.7%. The operational cost is increased due to the increased pressure drop but the overall impact is beneficial as Ctotal of equipment is reduced by ~52.7%.

SUMMARY Scn2a encodes the voltage-gated sodium channel NaV1.2, a main mediator of neuronal action potential firing. The current paradigm suggests that NaV1.2 gain-of-function variants enhance neuronal excitability, resulting in epilepsy, whereas NaV1.2 deficiency impairs neuronal excitability, contributing to autism. However, this paradigm does not explain why ~20%–30% of individuals with NaV1.2 deficiency still develop seizures. Here, we report the counterintuitive finding that severe NaV1.2 deficiency results in increased neuronal excitability. Using a NaV1.2-deficient mouse model, we show enhanced intrinsic excitability of principal neurons in the prefrontal cortex and striatum, brain regions known to be involved in Scn2a-related seizures. This increased excitability is autonomous and reversible by genetic restoration of Scn2a expression in adult mice. RNA sequencing reveals downregulation of multiple potassium channels, including KV1.1. Correspondingly, KV channel openers alleviate the hyperexcitability of NaV1.2-deficient neurons. This unexpected neuronal hyperexcitability may serve as a cellular basis underlying NaV1.2 deficiency-related seizures., Graphical Abstract, In brief Conventional wisdom suggests that the inadequacy of voltage-gated sodium channels impairs intrinsic neuronal excitability. Zhang et al. report that a severe deficiency of the NaV1.2 channel unexpectedly results in hyperexcitability of striatal medium spiny neurons with an elevated voltage threshold.

Telemedicine is now in vogue, allowing through computer and communication tools to be deployed in the field of health, such as cardiology, area in which it has shown interest, in international studies. As the population ages, older people are increasingly concerned with this innovative practice. We take a look at telemedicine projects in France concerning the elderly, in the field of cardiology.

The paper presents an economic optimization of a STHX with two commonly adopted (i.e., Kern and Bell-Delaware) and one rarely explored (i.e., Wills-Johnston) methods. A detailed numerical code concerning thermal, hydraulic, exergy, and economic analysis of STHX is developed for all three methods. Normalized sensitivity analysis, parametric study, and Genetic Algorithm are used to ascertain the most influential parameters and optimize the total cost. It is observed that the calculations made using the Wills-Johnston method were reasonably close to the Bell-Delaware method. While the Kern method showed a significant deviation in the shell side calculations because of the several assumptions in this method. The parametric analysis showed that increasing the mass flow rate and the number of baffles increased the operating cost because of an exponential increase in the pressure drops. Finally, the optimization reduced the heat transfer area by ~26.4%, capital cost by ~20%, operational cost by ~50%, total cost by ~22%, and the stream cost by ~21%.

Gasketed plate heat exchangers (PHXs) are frequently used as preheaters in thermal water desalination systems to preheat the intake seawater by recovering heat from the brine and distillate streams. The detailed design and analysis of PHXs as a preheater is not available in the desalination related studies. Rather, the heat transfer coefficients are calculated by simple empirical equations. The current study provides a comprehensive design procedure and analysis of these preheaters. In this regard, a numerical model is developed to investigate the thermal–hydraulic performance of PHXs under various operating conditions. First, the code is validated against the experimental data and then the effect of input parameters is studied. The results show that the feed flow rate and plate chevron angle are very important parameters for the heat transfer coefficient and pressure drop in PHXs. It is shown that the salinity does not affect the HX performance; however, the study also showed that the selection of fouling resistance is critical and it considerably disturbs the design parameters that govern the heat exchanger cost. Finally, the sensitivity analysis is presented to identify the most sensitive input parameters for the thermal–hydraulic performance of the heat exchanger.

Telemedicine is now in vogue, being deployed through computer and communication tools in various health fields, such as diabetology, nephrology, dermatology, neurology, and cardiology. With population ageing, geriatrics is coming into sharp focus. Telemedicine practices differ for home-based or institutionalized patients in long-term care homes. We take a look at telemedicine projects in France concerning the elderly.