Natural Cycle Research Articles

Organic Farming vs. Integrated Nutrient Management: A Comparative Review of Agricultural Productivity and Sustainability

In an era where sustainable agriculture is crucial for global food security and environmental preservation, organic farming and Integrated Nutrient Management (INM) have emerged as leading practices. This review paper offers a comprehensive comparison of these two approaches, focusing on their impact on agricultural productivity and sustainability. Organic farming, with its emphasis on reducing the use of chemical fertilizers, pesticides, growth hormones, and feed additives, aligns closely with the principles of sustainability. It enhances food quality, promotes soil health, and mitigates adverse environmental effects by encouraging natural recovery cycles. However, organic farming's limitations, such as lower yields and a more labour-intensive approach have prompted interest in innovative solutions that blend organic practices with modern technologies. Integrated Nutrient Management (INM) presents a compelling alternative. By combining organic, inorganic, and biological nutrient sources, INM seeks to optimize nutrient use efficiency and maintain soil health. This approach offers a flexible nutrient management strategy, balancing organic and inorganic inputs to maintain crop productivity while reducing environmental impact. Studies have shown that INM can improve soil properties, such as bulk density, porosity, and water-holding capacity, leading to enhanced crop yields and lower greenhouse gas emissions. The paper explores how INM's integrated approach not only stabilizes crop production but also supports the growth of soil microbes, providing a source of energy and organic carbon. By using a combination of specific microorganisms, organic matter, and minimal doses of inorganic fertilizers, INM can achieve a harmonious balance that reduces environmental pollution and ensures long-term soil fertility. Ultimately, this review underscores the potential of combining organic and INM practices to create a sustainable and productive agricultural system. Through a comparative analysis, the paper aims to guide researchers, policymakers, and farmers towards adopting strategies that foster agricultural sustainability without compromising productivity.

Developing a smart green supplier risk assessment system integrating natural language processing and life cycle assessment based on AHP framework: An empirical study

Global carbon reduction drives the transformations of corporations, emphasizing carbon and environmental impact within supply chains. A critical challenge in risk management is converting unstructured data into quantifiable information, and ruining the conversion often leads to ineffective risk assessments. While artificial intelligence is increasingly used in supply chain risk management, previous studies seldom integrate text analysis for risk extraction and lack accurate risk assessment methods. This study pioneers an intelligent green supplier risk assessment system integrating natural language processing (NLP) and life cycle assessment (LCA) based on an analytic hierarchy process (AHP) framework. The proposed approach utilizes NLP keyword extraction to identify and assess risk and uses LCA to uncover environmental risks, minimizing negative impacts. The text classification model attains 81.7 % accuracy, ensuring a trustworthy risk assessment system. The proposed method could significantly improve risk analysis efficiency, foster sustainable procurement, and elevate enterprise competitiveness in sustainable business practices.

Correlation of Pathology and Homoeopathic Theory of Miasm

Hahnemann the father of homoeopathy lived in an age when the science of pathology was still in its primitive stage. It was since about two decades after the death of Hahnemann that the science of pathology started to progress by various scientists. Today we find pathology with facts and daily enriching itself with new ones. Many persisting old terms have mostly changed. The keen and logical observer Hahnemann observed and deduced many facts and conditions for expressing which the modern terms were not available with him so he had no way other than to use some descriptive phrases or to use the various terms in current parlance of his time for denoting his observed or deduced facts and conditions. In this article an attempt has been done to co-relate the homoeopathic concept of disease with modern concept of medicine. Thus is Greek theory of disease, pathos is a manifestation of three factors. 1] First of all disease involves a pathogen, the negative dynamic influence which disrupts the state of health. A pathogen may be a disturbing physical, environmental or psychological influence that affects any of the three levels of being. It includes the exciting causes of acute diseases as well as the fundamental cause of chronic diseases. 2] We have the disease process which is a combination of specific nature the pathogen and the general reaction of the vital force against it. This includes the progression of a disease through its natural stages and cycles. This is normally called pathology, which includes signs and symptoms. 3] Thirdly a disease includes Ponos, the Greek word for toil. This is the strain that the pathological process places on the constitution and its energy reserves as it fights to restore the state of health. The general were and tear on the organism due to continuous adaptive and defensive reactions of the vital force against pathogenic influence also produces concomitant symptoms in the organism. If a disruption of normal homeostasis remains unresolved it leads to disorders of the mind and all systems of the organism. Co-relation of Pathology and Homoeopathy: Hahnemann tells us in the Organon that the complete expression of every symptom is that of sensation, location, and modality. Location of symptom is an element in pathology and many times it is the sole element. Pathology is one of the symptoms of the disease, as well as any other of its manifestations and if we do not consider it we are not prescribing in accord with the totality of symptoms. We also do not individualize the case if we do not properly consider pathology. Remedies prescribed for the disease when there is present only one of the important elements of the prescription, namely a symptomatic similarity or a pathological similarity, cannot cure and all that can be expected of them is to relieve temporarily or to palliate. When we come across any disease condition as a Homoeopathic physician, two basic pathological conditions will be observed and they are Reversible pathology and Irreversible pathology. These pathological changes are further classified in to Inflammation, Proliferation and Degeneration. The detail understanding of nature and characteristics of each of them can be correlated with miasmatic diseases. Inflammatory changes and Theory of Miasm: All symptom syndrome where septicaemia or toxaemia are present having Psora in the background. Proloferative changes aand Theory of Miasm: All such subacute infalmmatory changes have psoric origin and end pathological changes are classified under sycosis miasmatic disease. Degenerative changes and Theory of Miasm: All such cellular changes indicate destruction in the background along wih the loss of normal structure and loss of normal functions which indicated syphilis miasmatic disease. Conclusion: on the basis of above discussion we conclude that 1. Pathology indicates pathogen, disease process and response of individual towards this process. 2. Psora, Sycosis and Syphilis are chronic miasmatic diseases. 3. Only nosological terminology is not sufficient to corelate the the hahnemannian concept of Miasm with pathology. The origin, development, stage of disease and clinical manifestations are to be considered while corelating the concept of miasm with pathology. Refrences: 1. Dey, Text book of Pathology, New Delhi. 2. Ortega, Notes on Miasm, B jain Publication, New Delhi. 3. Symposium Volumes, ICR Publications. 4. www. similia. Com.

Do we Need a ‘New Strategy Paradigm’? No

AbstractBansal et al.'s Point piece, "Strategy's Ecological Fallacy: How strategy scholars have contributed to the ecological crisis and what we can do about it," calls for reforming the strategy field to focus on the natural environment, ecological cycles, and interconnections across natural and social levels, in service of value creation for ‘a defined ecosystem that comprises respect for the natural environment’. We doubt that such new foundations are necessary or useful. We argue that Bansal et al. misconstrue the evolution and content of strategy thinking; downplay the usefulness of existing tools for dealing with their issues of concern; overlook problems of measurement, collective action, government failure, and cronyism encouraged by their preferred policies; embrace an unnecessarily alarmist worldview; and underappreciate the social benefits of the market‐based institutions they criticize. We suggest instead that a market system based on clearly delineated property rights, prices that freely adjust to reflect scarcities, and an institutional environment that encourages entrepreneurship and innovation remains an underappreciated instrument for protection of the natural environment, one that is superior to centralized and regulatory alternatives.

Architectural Porosity: Reading The Change of Inhabitation in Urban Heritage Area

Architectural Porosity: Reading The Change of Inhabitation in Urban Heritage Area

Straw from Different Crop Species Recruits Different Communities of Lignocellulose-Degrading Microorganisms in Black Soil.

The biological degradation of plant residues in the soil or on the soil surface is an integral part of the natural life cycle of annual plants and does not have adverse effects on the environment. Crop straw is characterized by a complex structure and exhibits stability and resistance to rapid microbial decomposition. In this study, we conducted a microcosm experiment to investigate the dynamic succession of the soil microbial community and the functional characteristics associated with lignocellulose-degrading pathways. Additionally, we aimed to identify lignocellulose-degrading microorganisms from the straw of three crop species prevalent in Northeast China: soybean (Glycine max Merr.), rice (Oryza sativa L.), and maize (Zea mays L.). Our findings revealed that both the type of straw and the degradation time influenced the bacterial and fungal community structure and composition. Metagenome sequencing results demonstrated that during degradation, different straw types assembled carbohydrate-active enzymes (CAZymes) and KEGG pathways in distinct manners, contributing to lignocellulose and hemicellulose degradation. Furthermore, isolation of lignocellulose-degrading microbes yielded 59 bacterial and 14 fungal strains contributing to straw degradation, with fungi generally exhibiting superior lignocellulose-degrading enzyme production compared to bacteria. Experiments were conducted to assess the potential synergistic effects of synthetic microbial communities (SynComs) comprising both fungi and bacteria. These SynComs resulted in a straw weight loss of 42% at 15 days post-inoculation, representing a 22% increase compared to conditions without any SynComs. In summary, our study provides novel ecological insights into crop straw degradation by microbes.

Comparison of embryo development of ICSI and IVF derived embryos from modified natural cycles according to time-lapse technology

Comparison of embryo development of ICSI and IVF derived embryos from modified natural cycles according to time-lapse technology

Deformation and strength degradation mechanism of weathered mudstone soil during dry-wet process based on a developed DEM approach

The soils suffer dry-wet cycles in nature and engineering due to the change of temperature, rainfall and the fluctuation of the groundwater level. The shrinkage-swelling deformation and mechanical properties evolve with the variations of moisture content during a dry-wet process was investigated by laboratory dry-wet cycle tests of a weathered mudstone soil. A DEM approach was developed for simulating the mechanical behaviors during the dry-wet process of the studied soil, considering the shrinkage-swelling deformation by adjusting the shrinkage or swelling ratio of the clay aggregate particles. The irreversible shrinkage-swelling deformation mechanism and the strength degradation mechanism were revealed. The results showed the developed DEM simulations can represent the deformation and the mechanical properties of soils during the dry-wet process. The shrinkage rate of soil decreases with the moisture content from saturation value to 5%, due to the reduction of the shrinkage potence of the clay aggregates. The irreversible shrinkage deformation of soils during a dry-wet process is because the limit swell potence of clay aggregate particles during the wetting process, leading to the swell during the wetting less than the shrinkage during the drying process. The strength degradation was divided into reversible portion mainly affect by the moisture content, and the irreversible portion affected by the meso-crack evolution during the dry-wet process. The large increase of meso-crack number during the drying leads to the rapid reduction of irreversible soil strength, while the decrease of porosity leads the increase of particle contacts and healing of the irreversible soil strength.

How Carrying Capacity and Water Storage Capacity Are Doing Right Now in Mojokerto City ?

Water provision, a fundamental need of civilization, is necessary to balance population expansion in cities. Clean water supply is impacted by the deterioration of the environment brought on by the effects of civilization. As a result, it’s critical to understand how a region’s water availability and water demand combine to form its carrying capacity and capacity. This study aims to assess the capacity for carrying as well as the availability of clean water in Mojokerto City, Indonesia, which is situated in East Java. This study employs a technique whereby the connections between natural cycles are strengthened into mathematical modelling, which is then distributed utilising a grid system approach using ArcGis. The information used is secondary data, which contains both spatial (land cover and ecoregion) and non-spatial (population, index of environmental services for water suppliers, and average per capita water demand) information. With a total supply of 61,997,308.31 m3/year and a population of 133,303 according to the grid system, the study’ findings indicate that the City of Mojokerto generally has a status that has been exceeded or has a water deficit. The required amount of water is therefore 21,939,093 m3/year. The amount of clean water needed by the city of Mojokerto has therefore been exceeded by 40,058,215 m3/year.

Possibilities of reproductive function realization in patients with premature ovarian insufficiency

Premature ovarian insufficiency (POI) directly affects the reproductive health of women all over the world. Currently, the study of this pathology is becoming an increasingly important issue due to the widespread prevalence of premature menopause in the female population. In addition to genetic predisposition, an important role in the development of premature menopause is played by the increasing number of ovarian surgeries due to the development of surgery, as well as radiation and chemotherapy for cancer, leading to premature depletion of the follicular reserve in the ovaries. An important component of treatment for women with POI is not only the management of undesirable symptoms of menopause, prevention of cardiovascular complications and fractures due to decreased bone mineral density, but also the possibility of realizing their reproductive function in the future. Therefore, other treatment options may be offered to women with POI in the absence of spontaneous pregnancy in the natural cycle. Oocyte donation may be recommended for such women, but this treatment option may not be suitable if the patient wishes to have genetically related children. In such a case, oogonal stem cell transplantation, ovarian cortex fragmentation or PRP therapy are possible. In women who will undergo chemotherapy and radiation therapy for cancer, reimplantation of ovarian cortical tissue is recommended to preserve fertility. If there is a risk of malignant cell transfer with this treatment modality, primordial follicles can be isolated from ovarian tissue, cultured and activated in vitro, fertilized, and transferred into the uterine cavity. IVF with surrogate embryo transfer may be an alternative choice for a woman with NPT, which allows her to realize her reproductive plans.

Nanostructured S@VACNTs Cathode with Lithium Sulfate Barrier Layer for Exceptionally Stable Cycling in Lithium-Sulfur Batteries

Lithium-sulfur technology garners significant interest due to sulfur’s higher specific capacity, cost-effectiveness, and environmentally friendly aspects. However, sulfur’s insulating nature and poor cycle life hinder practical application. To address this, a simple modification to the traditional sulfur electrode configuration is implemented, aiming to achieve high capacity, long cycle life, and rapid charge rates. Binder-free sulfur cathode materials are developed using vertically aligned carbon nanotubes (CNTs) decorated with sulfur and a lithium sulfate barrier layer. The aligned CNT framework provides high conductivity for electron transportation and short lithium-ion pathways. Simultaneously, the sulfate barrier layer significantly suppresses the shuttle of polysulfides. The S@VACNTs with Li2SO4 coating exhibit an extremely stable reversible areal capacity of 0.9 mAh cm−2 after 1600 cycles at 1 C with a capacity retention of 80% after 1200 cycles, over three times higher than lithium iron phosphate cathodes cycled at the same rate. Considering safety concerns related to the formation of lithium dendrite, a full cell Si-Li-S is assembled, displaying good electrochemical performances for up to 100 cycles. The combination of advanced electrode architecture using 1D conductive scaffold with high-specific-capacity active material and the implementation of a novel strategy to suppress polysulfides drastically improves the stability and the performance of Li-S batteries.

Pregnancy Rates in Frozen-Thawed Embryos Derived from Donor Oocytes According To the Mid-Luteal Phase Endometrial Echo Pattern

Background: Previous studies have found a lower live delivered pregnancy rate (LDPR) when women have a triple-line (TL) endometrial echo pattern in mid-luteal phase in natural cycles, but not specifically when a donor oocyte was used. Objective: To determine if failure of progression of a triple line (TL) sonographic endometrial echo pattern despite supplemental progesterone (P) support in the luteal phase is associated with a LDPR following frozen embryo transfer (FET) where the embryos were derived from donor oocytes. Study Design/Materials and Methods: A retrospective review was performed over a twenty-year period of all FET cycles performed in women ≤ age 42 and women ≥ age 43 when the oocyte source was a fresh donor oocyte. All women were on the same regimen of maximum P where 100 mg of P in oil plus vaginal P once there was adequate endometrial thickness. All FETs occurred on day three. The live delivered pregnancy rates were determined and compared according to whether a TL echo pattern, isoechogenic (IE), or homogenic hyperechogenic (HH) was found on the seventh day of taking P. Results: No matter what age, the TL pattern was uncommon (<5%). Women aged > 43 showed a non-significant trend of about a 33% reduction in LDPRs if they continued with a TL pattern into mid-luteal phase. Conclusion: Identifying a TL mid-luteal echo pattern may help to identify a potential correctable reason for failure to conceive following transfer of embryos derived from younger donors in a small minority of women aged > 43.

Predicting post-fire hydrological and erosive catchment response during rainfall events. A comparison of OpenLISEM and MOHID Land models

Wildfires are a source of instability for the natural water cycle in forested watersheds, endangering the water quantity and quality reaching downstream water bodies. The faster hydrological response of a burned area leads to increased runoff and transport of sediment and ash particles during and after rainfall events. Therefore, the use of an adequate spatiotemporal resolution in hydrological models is necessary to properly estimate post-fire impacts. Especially when addressing hydrological events such as flash floods and debris flows, which are highly unpredictable and are characterized by short duration and high impact outside the burned area.This study aims to compare the ability of two hydrological models to simulate the hydrological response and sediment transport during the first year after a fire to ultimately understand which one would best serve as a post-fire hydrological predicting tool at event scale. To achieve this goal, OpenLISEM, an event-based hydrological model, and MOHID Land, a continuous model with variable timestep, were compared. Driven by several limitations identified in previous modeling exercises at this scale during the calibration phase, this work performed a parametrization through the variation in boundary conditions characterizing each event.OpenLISEM and MOHID Land models exhibited similar capabilities in simulating runoff during the first post-fire year. However, the larger erosion input parameters required by MOHID Land increase the complexity of erosion prediction and increase equifinality. In addition, MOHID Land limited capacity to perform sensitivity and uncertainty analyses emerged as a major disadvantage, hindering the assessment of the reliability of the model's predictions. Despite its limitations for not integrating subsurface flow and base flow, OpenLISEM is the most suitable model for assessing post-fire impacts on runoff and sediment production at the event scale, because of its ease of implementation and its reduced computational requirements.

IMPACTS OF CLIMATE CHANGE ON THERMAL BIOCLIMATIC INDICES OVER IRAQ

This study was aimed to investigate the trends in (11) thermal bioclimatic indicators throughout Iraq's various climates to better understand their spatiotemporal variations in different climates. All bioclimatic indicators have been calculated from daily ERA5 datasets of temperature extracted from 361 grid points covering Iraq. This data set covers global coverage of monthly temperatures from 1980 to 2022, with a spatial resolution of (0.25°x0.25°). Eleven thermal bioclimatic indicators were subjected to the Mann-Kendall (MK) test in order to measure trends in a single direction, without taking into account the influence of natural cycles. The findings showed that the majority of Iraq's thermal bioclimate indicators had changed. implying that rising temperatures have had a significant influence on the country's bioclimate. The annual mean temperature data revealed that Iraq had a considerable increase in Bio1 of (0.28 to 0.48) °C/decade, which is more than the )0.15( °C/decade worldwide average. The rise was found to be significantly greater in Iraq's northern and eastern regions. The analysis suggested that the diurnal temperature range decreased in most regions of Iraq, especially in the southern and northeastern sections. The maximum temperature increased most dramatically in the warmest quarter, whereas the changes in the coldest quarter were less noticeable, showing an increase in climatic extremes in Iraq. The study unequivocally shows that climate change is leading to an increase in the mean temperature, specifically during the warmest months of the year.

Fatty acid supplementation during warming improves pregnancy outcomes after frozen blastocyst transfers: a propensity score-matched study

This study aimed to examine the viability of human blastocysts after warming with fatty acids (FAs) using an in vitro outgrowth model and to assess pregnancy outcomes after a single vitrified-warmed blastocyst transfer (SVBT). For the experimental study, we used 446 discarded vitrified human blastocysts donated for research purposes by consenting couples. The blastocysts were warmed using FA‐supplemented (FA group) or non-FA-supplemented (control group) solutions. The outgrowth area was significantly larger in the FA group (P = 0.0428), despite comparable blastocyst adhesion rates between the groups. Furthermore, the incidence of outgrowth degeneration was significantly lower in the FA group than in the control group (P = 0.0158). For the clinical study, we retrospectively analyzed the treatment records of women who underwent SVBT in natural cycles between January and August 2022. Multiple covariates that affected the outcomes were used for propensity score matching as follows: 1342 patients in the FA group were matched to 2316 patients in the control group. Pregnancy outcomes were compared between the groups. The rates of implantation, clinical pregnancy, and ongoing pregnancy significantly increased in the FA group after SVBTs (P = 0.0091–0.0266). These results indicate that warming solutions supplemented with FAs improve blastocyst outgrowth and pregnancy outcomes after SVBTs.

Flood risk identification in high-density urban areas of Macau based on disaster scenario simulation

Currently, most of the world's economically developed and densely populated cities are built along coasts, and populations and industries tend to concentrate in coastal areas. However, with climate change, extreme weather events frequently occur in coastal areas. High-density urban spaces have changed the natural hydrological cycle, and the dense spatial layout, low-load municipal system planning, and inefficient management system of coastal cities have led to an increasing threat of flooding in these high-density urban areas, affecting their safety and sustainable development. In this context, the scientific and reasonable risk assessment of future flooding in coastal high-density urban areas has become an urgent problem and a key focus of urban disaster prevention and control efforts. In this paper, a flood identification tool is developed, a technical route for flood risk identification is established, identification scenarios under several disaster conditions are set, and classification criteria for flood risk identification are determined. An empirical study of high-density urban areas in Macau is carried out, the Infoworks Icm hydrological simulation software (Manufacturer: HR Wallingford (Shanghai) Co.,Ltd) is used to establish a flood hazard risk identification model for the Macau Peninsula, and flood hazard risk zones for the high-density urban areas in Macau are identified and delineated based on the simulation results.

Investigation of the indoor CO2 removal efficiency and fresh air energy savings of living walls in office spaces

Elevated indoor CO2 levels might have adverse effects on human health. However, conventional physical and chemical methods for indoor CO2 removal face the challenges of high energy consumption, low efficiency at low CO2 concentrations, and high costs. Furthermore, the introduction of outdoor air to lower indoor CO2 concentrations results in significant HVAC energy consumption. Aligning with office hours and the natural light cycle, the utilization of photosynthesis in living walls (LWs) offers an energy-efficient and sustainable solution for the mitigation of high CO2 levels in office spaces. This study experimentally investigates the impacts of the carbon fixation pathways, light flux density, and substrate moisture content on the CO2 removal rate of LWs in two identical rooms. The findings provide practical suggestions for plant species selection, lighting design, and irrigation management in office spaces to enhance the CO2 removal efficiency of LWs. Additionally, the fresh air energy-saving effects of LWs under different scenarios are accurately simulated in EnergyPlus. The results demonstrate that choosing C3 plants over CAM plants in LWs yields higher CO2 removal efficiency. The activation of artificial lighting is recommended when the surface light flux density of LWs drops below the light compensation point (LCP), ensuring favorable conditions for growth. In a 30-m2 office room accommodating two and three occupants, LWs can respectively reduce the demand for fresh air by 13.9 %–38.5 % and decrease fresh air energy consumption by 11.2 %–28.2 %.

Ongoing pregnancy rates in single euploid frozen embryo transfers remain unaffected by female age: a retrospective study

Research questionIs female age a significant factor in the likelihood of an ongoing pregnancy in single euploid frozen embryo transfers (seFET)? DesignRetrospective study of 1923 seFET cycles from 1464 women, either in a natural cycle (NC) or a hormonal replacement therapy cycle. Outcome was the ongoing pregnancy rate (OPR). ResultsThere were 990 (51.48%) ongoing pregnancies among 1923 included transfers. The OPR were 51.4%, 49.1%, 53.3% and 52.3% for women aged ≤35, >35 to ≤37, >37 to ≤40, and >40 years-old at OPU without a significant trend for decreasing OPRs (P=0.679). No significant differences between the groups (OPR vs. no pregnancy or miscarriage) were seen for female age at transfer (P=0.609) or at OPU (P=0.816). Women who received good quality embryos (P<0.001), with lower BMI (P<0.001), at least one previous pregnancy (P<0.001) and a NC (P<0.001) had significantly higher OPR. Multivariable regression (adjusted for BMI, embryo quality, endometrial preparation) analysis did not show a significant effect of female age at OPU on achieving an OPR. Compared to women ≤35-year-old, none of the age groups had significantly higher or lower pregnancy rates. A multinomial regression analysis showed that both, miscarriage and no pregnancy vs. ongoing pregnancy was associated with BMI, embryo quality and endometrial preparation. Again, female age had no significant associations with either outcome. Conclusion(s)The herein presented data demonstrate no substantial impact of female age on its own on the OPR in seFET cycles, but a significant impact of embryo quality, BMI, previous parity and a NC protocol.

Menstrual cycle phases and dosage of synthetic hormonal contraceptives influence diurnal rhythm characteristics of distal skin temperature

ABSTRACT This study aimed to explore how natural menstrual cycle phases and dosage of oral hormonal contraceptives (OC) influence the diurnal rhythm of distal skin temperature (DST) under real-life conditions. Participants were 41 healthy females (23.9 ± 2.48 y), comprising 27 females taking monophasic hormonal oral contraceptives (OC users) and 14 females with menstrual cycles (non-OC users). Wrist DST was continuously recorded and averaged over two consecutive 24-hour days during (pseudo)follicular and (pseudo)luteal menstrual phases. Diurnal rhythm characteristics, i.e. acrophase and amplitude, describing timing and strength of the DST rhythm, respectively, were calculated using cosinor analysis. Results show that non-OC users experienced earlier diurnal DST maximum (acrophase, p = 0.019) and larger amplitude (p = 0.016) during the luteal phase than during the follicular phase. This was observed in most (71.4%) but not all individuals. The OC users showed no differences in acrophase or amplitude between pseudoluteal and pseudofollicular phases. OC users taking a higher dosage of progestin displayed a larger amplitude for DST rhythm during the pseudoluteal phase (p = 0.009), while estrogen dosage had no effect. In conclusion, monophasic OC cause changes in diurnal DST rhythm, similar to those observed in the luteal phase of females with menstrual cycles, suggesting that synthetic progestins act in a similar manner on skin thermoregulation as progesterone does.

Performance and cost potential for direct-fired supercritical CO2 natural gas power plants

Direct-fired supercritical CO2 (sCO2) power cycles are being explored as an attractive alternative to natural gas combined cycle (NGCC) plants with carbon capture and storage (CCS). Therefore, understanding their performance and cost potential is important for the commercialization of the technology. This study presents detailed techno-economic optimization results of natural gas-fired, utility-scale power plants based on the direct sCO2 power cycle, which is lacking in public literature. The study considered multiple plant configurations with varying levels of thermal integration with the plant air separation unit (ASU) to shows the systematic impact of thermal integration on plant performance and economics. Several design variables for each power cycle configuration were identified and optimized to minimize the levelized cost of electricity (LCOE). The optimized direct sCO2 power plants achieved ∼48 % plant efficiency (HHV basis) which is similar or slightly higher plant efficiencies than state-of-the-art NGCC plants based on the F-class gas turbine with carbon capture and storage (CCS). The LCOE of the optimized direct sCO2 plants is 13–17 % higher than the reference NGCC plants with CCS due to high capital costs associated with the ASU and sCO2 power block, though there is significant room for improvement due to high uncertainty in component capital costs for these new plants. Based on the results, direct sCO2 power cycles have the potential to achieve >50 % efficiency (HHV basis) with >98 % CO2 capture rate which can lead to significant efficiency improvement and CO2 emissions reductions compared to NGCC plants with CCS.