Optimal Humidity Research Articles

Prediction of Storage Conditions to Increase the Bioenergy Efficiency of Giant Miscanthus Pellets Produced through On-Site Integrated Pretreatment Machines

Fossil fuels are associated with problems such as resource depletion and pollution, necessitating the exploration of alternatives. Giant miscanthus (Miscanthus × giganteus Greef et Deu), a perennial that can be harvested yearly, requires a low production energy input. It has less ash content and high heat efficiency and has attracted attention as an energy source. An on-site processing equipment, powered via a tractor and equipped with a chipper and a two-stage compression roller, was developed that can harvest 1000 kg of giant miscanthus per hour and simultaneously produce compressed pellets eliminating unnecessary processes such as transportation and processing. With its use, 33–74.5 kWh/t of electrical energy can be saved by producing pellets. The changes in moisture content between the produced compressed pellets and two samples of the ground product were measured immediately before compression for 24 h at relative humidity ranging from 65% to 80%. The moisture content was 6% initially; it ranged from 6.71% to 7.81% in compressed pellets, depending on the conditions, and from 7.44% to 9.82% in the ground sample immediately before compression, indicating the effect of the physical form of the biomass and humidity in the environment. The possible storage period (while maintaining the moisture content at 8–10% for optimal biofuel efficiency based on the measured data) was predicted. The optimal relative humidity of the storage environment for maintaining biomass quality for more than 6 months was predicted to be ≤77% and ≤70% for the compressed pellet and ground sample, respectively. Moreover, at a relative humidity ≥77%, giant miscanthus biomass, immediately before compression, had >10% moisture content in 2 days, warranting caution in storage.

ОСОБЛИВОСТІ РОЛІ ҐРУНТОВОЇ ВОЛОГИ В ЗАБЕЗПЕЧЕННІ ВИСОКОЇ ВРОЖАЙНОСТІ РОСЛИН ЦИКОРІЮ КОРЕНЕПЛІДНОГО

У статті наведено результати польових досліджень з вивчення впливу ґрунтової вологи на врожайність рослин цикорію коренеплідного та визначення вмісту форм води в рослинах на різних за родючістю ґрунту ділянках із внесенням органічних добрив 20 т/га. Установлено, що за найбільш інтенсивного росту та розвитку рослин на удобрених ділянках упродовж вегетаційного періоду накопичували у ґрунті більш високий відсоток загальної та вільної води і менше зв’язаної, порівняно з ділянками, де не вносили органічних добрив. За вмістом загальної води в рослинах різниця була незначною, особливо в денні години. Отже, внесення органічних добрив у ґрунт під цикорій коренеплідний з метою одержання високої врожайності дає можливість краще зберегти у ґрунті ґрунтову вологу, що надалі впливає на врожайність культури.

Investigation on the effective substrate for high yields of Pleurotus ostreatus: A case study of Kinyerezi Tanzania

Investigation on what substrate combination is more effective in producing high yields of Pleurotus ostreatus in local greenhouses was conducted at Kinyerezi (6°50'27.2"S, 39°10'26.5"E) in Dar es Salaam in 2020 aiming to produce a substrate protocol which will maximize yielding of mushrooms in local greenhouses. Sugar, grain chaff, and lime were added in specified ratios to the compost of sliced banana leaves and sawdust and followed by sterilization for 4 hours and cooling for 24 hours before being packaged in 1 kg bags for fungal inoculation. 450 plastic bags of compost were inoculated with mushroom spores and left for 28 days for colonization. The compost was sparingly watered to maintain the optimal humidity, temperature, and pH for the germination of mushrooms. Mushroom germination in 100 bags with additional sugar,100 bags with additional grain chaff, and 100 bags with additional lime were monitored for four months where germination percentage and germination number were recorded monthly and used for statistical analysis. Bags with additional sugar indicated a significant difference in the monthly germination percentage (P=0.002248, df = 2). Additional sugar descriptively increased germination number from 30 to 173 than other substrates which increased from 0.5 to 16.5. However, the increase was statistically not significant P=0.25246, df = 2. Mushroom growers are advised to use the compost formula as indicated in this investigation as a new knowledge contributed by the research. The use of added sugar as a substrate in the compost is mandatory.

Predicting the future climate-related prevalence and distribution of crop pests and diseases affecting major food crops in Zambia

Environmental factors determine the suitability of natural habitats for crop pests and often facilitate their proliferation and that of the crop diseases they carry. Crop pests and diseases damage food crops, significantly reducing yields for these commodities and threatening food security in developing, predominantly agricultural economies. Given its impact on environmental factors, climate change is an important determinant of crop pest and disease distribution. This study uses Targeting Tools, a climate suitability analysis and mapping toolkit, to explore the potential impact of climate change on select environmental factors linked to crop pest and associated diseases’ proliferation. Based on the existing literature, prediction modeling was performed on 21 key pests and diseases that impact the major food crops for Zambian consumption. Future changes in habitat suitability for these crop pests and diseases were mapped based on their optimal temperature and relative humidity conditions for proliferation. Results project that there will be an overall increased geographical spread of suitable habitats for crop pests (and as follows, crop diseases) that thrive in warmer environments. By the 2030s, crop pests and diseases will increasingly spread across Zambia, with a higher likelihood of occurrence projected under RCPs 2.6, 4.5, and 8.5. Crop pests and diseases that thrive in cooler environments will experience decreasing habitat suitability in the 2030s, but will transition to a slower decrease in the 2050s under RCPs 2.6 and 4.5. Overall crop pest and disease habitat suitability will continue to rise slowly in the 2050s; RCP 8.5 shows an increased habitat suitability for crop pests and diseases that thrive in warm environments, with a decreased likelihood of occurrence for crop pests and diseases that thrive in cooler environments. The results highlight the need for future-facing, long-term climate adaptation and mitigation measures that create less suitable microclimates for crop pests and diseases.

Humidification Performance Evaluation of hollow-fiber membrane-based humidifier for air-conditioning

Indoor viral and fungal activity is affected by the concentration of moisture in the air. Since the concentration of viruses and fungi in the air directly affects the human body, it is necessary to maintain a specific humidity range through the air-conditioning system. The optimum humidity in the building is 40-60%, and it needs to be maintained regardless of the season. In winter, a separate humidification system is required to adjust the indoor humidity due to the dry outside air. However, since the conventional humidification system injects water or steam directly into the air, various problems, such as water pollution, occur. Therefore, this study proposed a new humidification method called the hollow-fiber membrane humidification system to increase indoor humidity, and the effect was experimentally evaluated. When 150 CMH (air volume of ventilation level) was supplied, the absolute humidity increased by about 4.14g/kg compared to the initial condition, and the relative humidity of the indoor supply air increased to about 64%.

Analysis of the operation of the device for the introduction of meliorants

The device for applying meliorants is designed for the distribution of nutrients, presented in liquid form, in the sublap space of a plane-cutting tillage tool. Distribution is carried out by spraying liquid meliorants, which allows you to saturate the fertile soil layer with nutrients and substances to obtain a high yield. Spraying of liquid meliorants occurs due to the directional effect of compressed air on the liquid jet, as a result of which the jet breaks up into a finely dispersed medium, which makes it possible to moisten a significant part of the plow sole and the soil layer being cut. The formed layer, when falling from the dump of the working body to the plow sole, is destroyed and a favorable condition is created for the distribution of nutrients in the treated soil layer. Also, the optimal humidity necessary for the growth of crops is normalized and preserved from volatilization.

Investigation of organophosphorus (OPs) compounds by a needle trap device based on mesoporous organo-layered double hydroxide (organo-LDH).

Organophosphorus (OPs) compounds can endanger human health and the environment by inhibiting the acetylcholinesterase enzyme. But these compounds have been widely used as pesticides due to their effectiveness against all kinds of pests. In this study, a Needle Trap Device (NTD) packed with mesoporous organo-layered double hydroxide (organo-LDH) material and coupled with gas chromatography-mass spectrometry (GC-MS) was employed for the sampling and analysis of OPs compounds (diazinon, ethion, malathion, parathion, and fenitrothion). In this way, the [magnesium-zinc-aluminum] layered double hydroxide ([Mg-Zn-Al] LDH) modified with sodium dodecyl sulfate (SDS) as a surfactant was prepared and characterized by FT-IR, XRD, BET, and FE-SEM, EDS, and elemental mapping techniques. Then, various parameters such as relative humidity, sampling temperature, desorption time, and desorption temperature were evaluated by the mesoporous organo-LDH:NTD method. The optimal values of these parameters were determined using response surface methodology (RMS) and central composite design (CCD). The optimal temperature and relative humidity values were obtained as 20 °C and 25.0%, respectively. On the other hand, the desorption temperature and time values were in the range of 245.0-254.0 °C and 5 min, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were reported in the range of 0.02-0.05 mg m-3 and 0.09-0.18 mg m-3, respectively, which shows the high sensitivity of the proposed method compared to the usual methods. The repeatability and reproducibility of the proposed method (by calculating the relative standard deviation) was estimated in the range of 3.8-10.10 which indicates the acceptable precision of the organo-LDH:NTD method. Also, the desorption rate of the stored needles at 25 °C and 4 °C, was determined to be 86.0% and 96.0%, respectively after 6 days. The results of this study proved that the mesoporous organo-LDH:NTD method can be utilized as a fast, simple, environmentally friendly, and effective method for sampling and determining OPs compounds in the air.

A review study on the design and control of optimised greenhouse environments

Abstract Greenhouses are inflated structures with transparent covering that are used to grow crops under controlled climatic conditions. Crops are protected from extreme climate-related events by being enclosed. Furthermore, the greenhouse design ratio impacts the temperature and humidity distribution profile uniformity as well as the greenhouse. As a result, by effectively designing the greenhouse structure, building materials, dimensions, and shapes, the cost of cooling management strategies can be reduced. Structures with changed arch shapes showed to be more effective at reducing greenhouse cooling demands in hot areas. To demonstrate the tropical region’s inherent capabilities for generating a proper atmosphere for plant development, the optimal temperature, humidity, light, and PH for greenhouse production of crops were supplied. Greenhouse cooling systems are dominated by local environmental characteristics that have an immediate impact on their indoor climatic conditions. Photovoltaic systems in greenhouses have proven technological capacity in real-world settings in this area. This could increase the energy efficiency of some agrivoltaic greenhouse design options.

The Effect of Global Warming on The Incidence of Malaria: Distribution of Anopheles sp. in Indonesia

Malaria is an infectious disease caused by the female Anopheles mosquito vector. Malaria is still a cause of death worldwide, especially in young children. Malaria prevention needs to be done comprehensively so that it can be overcome optimally, one of which is the anopheles vector. Anopheles' development is influenced by the environment. World warming dramatically affects the development of anopheles because it requires an optimal temperature of 25-32oC to go through the life cycle to produce adult mosquitoes. Studies on the effect of global warming on anopheles’ resistance are needed in order to know how mosquito resistance is to global warming and can take precautions to prevent mosquito breeding. A systematic literature review. We search keywords climatic change, global warming, anopheles, malaria, and Indonesia in Pubmed, Google, and ResearchGate. We found 30 kinds of literature and screening based on inclusion criteria, and last, we only have 13 articles that we analyzed to answer our questions. A literature search showed that Anopheles's development is influenced by the environment. Anopheles likes the tropics because it has optimal temperature and humidity. The majority of Anopheles that vector simian malaria also cause malaria in humans. Indonesia has a diversity of anopheles spread from Sumatra to Papua. Global warming, which can increase the earth's temperature, has an influence on the development of Anopheles mosquitoes as vectors of malaria Introduction

Efficacious removal of benzene and ammonia gases over visible light irradiated activated carbon

Removal efficiencies of benzene and ammonia were studied using as-received commercial activated carbon (AC) at 0%, 30%, and 60% relative humid (RH) conditions with and without visible light irradiation. We showed that light enhanced the removal efficiency of benzene even under nitrogen, and the enhancement effect became more pronounced in the presence of H2O and O2. We also demonstrated that the ammonia removal efficiency can be enhanced by visible light irradiation under optimum humidity conditions. We further suggested more efficient migration of NH3 through the nanoporous channels of AC facilitated by light and water. Fourier-transform infrared (FT-IR) analyses addressed the changes in surface structure of AC caused by oxidizing agents such as OH. radicals created with light irradiation and other reagents.

Evaluating the effects of indoor air quality on teacher performance using artificial neural network

PurposeA building's Indoor Air Quality (IAQ) has a direct impact on the health and productivity on its occupants. Understanding the effects of IAQ in educational buildings is essential in both the design and construction phases for decision-makers. The purpose of this paper is to outline the impact air quality has on occupants' performance, especially teachers and students in educational settings.Design/methodology/approachThis study aims to evaluate the effects of IAQ on teachers' performances and to deliver air quality requirements to building information modelling-led school projects. The methodology of the research approach used a quasi-experiment through questionnaire surveys and physical measurements of indoor air parameters to associate correlation and deduction. A technical college building in Saudi Arabia was used for the case study. The study developed an artificial neural network (ANN) model to define and predict relationships between teachers' performance and IAQ.FindingsThis paper contains a detailed investigation into the impact of IAQ via direct parameters (relative humidity, ventilation rates and carbon dioxide) on teacher performance. Research findings indicated an optimal relative humidity with 65%, ranging between 650 to 750 ppm of CO2, and 0.4 m/s ventilation rate. This ratio is considered optimum for both comfort and performanceOriginality/valueThis paper focuses on teacher performance in Saudi Arabia and used ANN to define and predict the relationship between performance and IAQ. There are few studies that focus on teacher performance in Saudi Arabia and very few that use ANN in data analysis.

Desain and Build a Medium Voltage Cubicel Temperature and Humidity Optimization Tool to Minimize the Occurrence of Corona Disease with the PLC-Based Fuzzy Method

Cubicle is an electrical device that functions as a breaker, protector, connector, controller, and divider of the power system electricity from a power source and reduce sparks when connecting. One of the problems that occur in medium voltage cubicles is the presence of corona. Corona phenomena at cubicle terminations can trigger disturbances such as a decrease in insulation quality, power loss and a significant increase in harmonic distortion. Based on previous research, the solution to minimize the occurrence of corona is to optimize the temperature and humidity of the cubicle. Many of the previous studies examined the control of cubicle temperature and humidity using fans and heaters, but the temperature and humidity had not yet reached a stable and optimal point. In this study, raised a problem regarding the optimization of temperature and humidity in cubicles using the fuzzy method to stabilize the performance of medium voltage cells. In this study, it was found that the fuzzy method in this prototype was able to stabilize the panel humidity at 55% RH and stabilize the panel room temperature at 31.5 o C. Thus, it is hoped that a stable and optimal temperature and humidity can minimize the occurrence of corona. The use of HMI/SCADA based applications can facilitate the ability of the user (operator) to monitor several available parameters and manually control the operation of the panel (on/off).

Ni-Co-P hollow nanobricks enabled humidity sensor for respiratory analysis and human-machine interfacing

Metal phosphide has been widely exploited in the field of energy storage and catalysis instead of chemical sensors. In this work, Ni-Co-P hollow nanobricks (HNBs) was developed via template synthesis method followed by etching and phosphating treatments. The hierarchical morphology and composition of the Ni-Co-P HNBs were respectively characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), nitrogen sorption analysis and transmission electron microscopy (TEM). High sensitivity (~ 3.6 kΩ / % RH), low hysteresis (~ 3% RH) and good repeatability were achieved in a wide moisture range from 0% RH to 97.5% RH. By adjusting the ratio of Ni and Co, humidity sensing performance can be efficiently modulated. The optimal humidity sensing properties were attained at a ratio of Ni and Co of 1:5. Finally, the as-prepared sensor demonstrates great capability in respiratory analysis and noncontact human-machine interfacing. This work opens up a new paradigm for developing high-performance wearable sensing devices. • Metal phosphides Ni-Co-P are employed to fabricate humidity sensor. • The hierarchical hollow nanobricks endows a large surface area and abundant adsorption sites to interact with water molecules. • The optimal humidity sensing properties are attained at a ratio of Ni and Co of 1:5. • The sensor enables non-contact monitoring of breath and limb motions.

A critical review on the influence of humidity for plant growth forecasting

Relative humidity of ambient air is a critical parameter for crop production as it influences the water balance and photosynthesis process in the plants. A comprehensive review on leafy, fruiting, flowering plants and grains were conducted to determine the effects of varying humidity levels on plant growth. Data from published works concluded that the plant growth improved with increasing humidity, as higher humidity conditions help to keep the stomata open to maintain the photosynthesis process and minimize evaporation process of the plants. By using regression analysis, it is forecasted that the increase in the air relative humidity by 10% would increase the leaf length, width and aerial dry weight for Lactuca Sativa by 10±3%, 2±5% and 28±3% respectively. The data trend suggests that the optimal relative humidity that could improve plant growth is 85±2%, as low humidity below optimum level will increase stomatal resistance, which leads to a reduction of carbon dioxide uptake and photosynthesis rate. Inversely, relative humidity above the optimal levels will adversely reduce the transpiration rate, which negatively affects the plant growth and leaf development due to impaired nutrient assimilation. The outcome of this study provides an insight for the development of plant growth forecasting model.

Impact of humidity in triple cation perovskite solar cells: Surface analysis

Perovskite (PVSK) is widely used in the absorber layer of solar cells due to its excellent conversion efficiency; however, these devices are highly susceptible to humidity. Furthermore, the mechanism underlying the moisture-induced performance degradation in triple cation PVSK has yet to be elucidated. In the current study, we used the anti-solvent method to prepare triple cation PVSK films in order to study the growth mechanism and influence of moisture on conversion performance. We determined that an appropriate quantity of moisture in PVSK films can improve grain growth of PVSK and increase the difference in potential energy between grain and grain boundary, thereby facilitating the transport and collection of carriers across grain boundaries. Excess moisture entering PVSK thin films leads to degradation of the PVSK absorber layer, resulting in the formation of PbI2, PbBr2, HI, FAI, and MABr, while leaving holes in the surface, which can compromise the stability of the crystals and efficiency of the solar cell. In the current study, the efficiency of PVSK thin film solar cells was 19.14% under an optimal humidity level 25%, which resulted in photoelectric characteristics and device efficiency on par with the results obtained under a pure nitrogen environment.

Relationship of Water Temperature and Air Humidity with Aedes Sp. Manggarai Tebet Village South Jakarta in 2022

Environmental-based diseases are still a health problem for the people of Indonesia. One of the diseases caused by environmental sanitation conditions that do not meet health requirements is dengue hemorrhagic fever. Several environmental factors such as temperature, air, and the intensity of lighting that enter the house are thought to strengthen the occurrence of dengue fever. The presence of mosquito larvae is an indicator that will greatly affect the presence of mosquito populations in a place. This study aims to determine the relationship between water temperature and air humidity with the presence of Aedes sp . in RW. 03 Kelurahan Manggarai, Kecamatan Tebet, South Jakarta in 2022. This research is a descriptive analytic study with a cross sectional study design . The research location in RW 03 is located in Manggarai Village. The total population in this study amounted to 298 houses, while the sample in this study amounted to 75 houses. The sampling technique that the writer uses is cluster random sampling . The results of the study were statistically tested with the chi-square test at a 95% confidence level. The result is that there are 8 houses that found larvae (10.70%) and larvae were found in 19 containers (10.74%). The type of landfill that found the most larvae was buckets totaling 16 (9.04%). With the larva-free rate (ABJ) in RW 03 Manggarai Village, Tebet District, South Jakarta of 89.33%, House Index (HI) of 10.67%, Container Index (CI) of 9.73%, and Breteau Index (BI) by 24. Most of the houses found Aedes sp . In containers with non-optimal temperature (>27 o C) as many as 64 houses (85.30%) and optimal humidity (70-80%) for the growth of Aedes sp . A total of 67 houses (10.70%). Statistical analysis showed that there was a relationship between water temperature and the presence of Aedes sp. ( p-value = 0.000) and there is no relationship between air humidity and the presence of Aedes sp larvae . ( p-value = 0.301). To reduce the presence of Aedes sp . It is suggested that every family member must work together to prevent Aedes sp. where people can live a clean and healthy life, by regulating the air circulation in the house and eliminating the Aedes aegypti mosquito breading place .

New UV-LED frontal flow photocatalytic reactor for VOCs treatment: Compactness, intensification and optimization studies

This study investigates and provides a solution for optimizing the photocatalytic treatment of toxic gases based on the use of TiO2 media deposited on luminous textiles. The target was the cyclohexane referent for the type A gas filtration tests. The photocatalytic supports were characterized by scanning electron microscopy. Then, the experiments conducted on a batch reactor showed that the TiO2-coated optical fiber media (in situ illumination configuration) performs better than conventional configuration (cellulosic TiO2 with external radiation ''UV lamp''. To take advantage of the new optical fiber media configuration, an intensification study was carried out by increasing the amount of TiO2 in the media and UV intensities of LED. Increasing these two parameters leads to an approximately fourfold increase in the degradation rate. The continuous treatment allowed the study to highlight the efficiency of the new configuration of the front flow reactors developed (PFR-LED) compared to the conventional configuration. This increased efficiency is demonstrated by the fourfold increase in the specific degradation rate of the optimized PFR-LED compared to the conventional reactor. The performance evaluation of the compact and optimized configurations of the frontal flow reactor (PFR-LED Optimized) aimed to highlight the influence of the inlet concentration under different flow rates. Furthermore, the effect of the number of optical fiber supports shows that the degradation rate and selectivity are enhanced. The results were obtained using four photocatalytic media (4OF/4UV-LED) for 1.19 mmol·m−3 of cyclohexane input concentration at 18 L.min−1 of flow rate under optimal humidity conditions (38 %), constituting the ultimate rate of CO2 selectivity achieved (31 %) for an abatement of 59 %.This global investigation has allowed for the design of a new version of a compact reactor. This reactor provides an economical and efficient way to eliminate gaseous pollutants, which clearly meets the main aims of the UN Sustainable Development Goals (UN SDGs).

“Born with a silver spoon in the mouth has bad sides too”: Experimentally increasing growth rate enhances individual quality but accelerates reproductive senescence in females of the mealworm beetle, Tenebrio molitor

Senescence occurs because of the decline of the strength of selection with age, allowing late-life reduced performances not being counter selected. From there, several phenomena may explain late-life reduced performances, such as the accumulation of deleterious mutations, the expression of pleiotropic genes or the existence of resource trade-offs between early and late performances. This latter phenomenon is at the core of the disposable soma theory of aging, which predicts that growth and early-life reproduction have costs that increase reproductive and actuarial senescence. Whereas the impact of the cost of early reproduction on reproductive and actuarial senescence has been extensively studied, that of the cost of growth remains overlooked and often inconclusive, possibly because of confounding effects associated with the procedures used to manipulate growth rate. Here, we investigated the cost of growth rate and its impact on reproductive senescence and longevity of females of the mealworm beetle, Tenebrio molitor. For this purpose, we generated insects with contrasted growth rates by raising groups of them in conditions below, above and optimal relative humidity (RH: 55, 85 and 70%, respectively) during the larval stage. The resulting adult females then bred, under the same optimal RH conditions, early in life, then later in life and were followed there until death. We found that larvae grown under the highest relative humidity exhibited the highest larval growth rate, thanks to both shorter growth duration and the achievement of heavier pupae mass. Adult females from this favorable growing condition lived longer, were more fecund early in life, but suffered from lower late-life reproductive investment. Our study shows that growth rate, which is highly dependent on the early-life environment, is an important factor modulating adult reproductive senescence, through the occurrence of early-late life trade-offs.

Effects of Relative Humidity and Paper Geometry on the Imbibition Dynamics and Reactions in Lateral Flow Assays

Lateral flow assays and paper microfluidics have the potential to replace benchtop instrumented medical diagnostic systems with instrument-free systems that rely on passive transport of liquid through micro-porous paper substrates. Predicting the imbibition dynamics of liquid through dry paper substrates is mostly modeled through the Lucas-Washburn (LW) equations. However, the LW framework assumes that the fluid front exhibits a sharp boundary between the dry and wet phases across the liquid imbibition interface. Additionally, the relative humidity in the environment results in moisture trapped within the pores of the paper substrates as the paper attains an equilibrium with the ambient air. Here, we apply a two-phase transport framework based on Brooks and Corey's model to capture imbibition dynamics on partially saturated paper substrates. The model is experimentally validated and is then used to predict the liquid-paper imbibition dynamics in simulated environments with 1-70% relative humidity. The model was also used to determine the saturation gradient of liquid along the imbibition interface of the paper substrate. Insights from these studies enabled us to determine the mechanism of the liquid transport in partially saturated porous paper substrates. The model also enabled us to evaluate the optimal paper shapes and relative humidity of the environment that maximize imbibition rates and minimize imbibition front broadening. Finally, we evaluate the effect of moisture content of paper on the rate of paper-based biochemical reaction by amplifying a sequence of the SARS-CoV-2 RNA target via reverse transcriptase loop-mediated isothermal amplification. Taken together, this study provides some important guidelines to academic and applied researchers working in point-of-care diagnostics to develop paper-based testing platforms that are capable of functioning in a robust manner across multiple environmental conditions.

Managing energy-water-carbon-food nexus for cleaner agricultural greenhouse production: A control system approach

Poverty, food insecurity and climate change are global issues facing humanity, threatening social, economic and environmental sustainability. Greenhouse cultivation provides a potential solution to these challenges. However, some greenhouses operate inefficiently and need to be optimized for more economical and cleaner crop production. In this paper, an economic model predictive control (EMPC) method for a greenhouse is proposed. The goal is to manage the energy-water‑carbon-food nexus for cleaner production and sustainable development. First, an optimization model that minimizes the greenhouse's operating costs, including costs associated with greenhouse heating/cooling, ventilation, irrigation, carbon dioxide (CO2) supply and carbon emissions taking into account both the CO2 equivalent (CO2-eq) emissions caused by electrical energy consumption and the negative emissions caused by crop photosynthesis, is developed and solved. Then, a sensitivity analysis is carried out to study the impact of electricity price, supplied CO2 price and social cost of carbon (SCC) on the optimization results. Finally, a model predictive control (MPC) controller is designed to track the optimal temperature, relative humidity, CO2 concentration and incoming radiation power in presence of system disturbances. Simulation results show that the proposed approach increases the operating costs by R186 (R denotes the South African currency, Rand) but reduces the total cost by R827 and the carbon emissions by 1.16 tons when compared with a baseline method that minimizes operating costs only. The total cost is more sensitive to changes in SCC than that in electricity price and supplied CO2 price. The MPC controller has good tracking performance under different levels of system disturbances. Greenhouse environmental factors are kept within specified ranges suitable for crop growth, which increases crop yields. This study can provide effective guidance for growers' decision-making to achieve sustainable development goals.