Axis System Research Articles

Estimating the Inertia Tensor Components of an Asymmetrical Spacecraft When Removing It from the Operational Orbit at the End of Its Active Life

The paper presents a method for estimating the inertia tensor components of a spacecraft that has expired its active life using measurement data of the Earth’s magnetic field induction vector components. The implementation of this estimation method is supposed to be carried out when cleaning up space debris in the form of a clapped-out spacecraft with the help of a space tug. It is assumed that a three-component magnetometer and a transmitting device are attached on space debris. The parameters for the rotational motion of space debris are estimated using this measuring system. Then, the known controlled action from the space tug is transferred to the space debris. Next, measurements for the rotational motion parameters are carried out once again. Based on the available measurement data and parameters of the controlled action, the space debris inertia tensor components are estimated. It is assumed that the measurements of the Earth’s magnetic field induction vector components are made in a coordinate system whose axes are parallel to the corresponding axes of the main body axis system. Such an estimation makes it possible to effectively solve the problem of cleaning up space debris by calculating the costs of the space tug working body and the parameters of the space debris removal orbit. Examples of numerical simulation using the measurement data of the Earth’s magnetic field induction vector components on the Aist-2D small spacecraft are given. Thus, the purpose of this work is to evaluate the components of the space debris inertia tensor through measurements of the Earth’s magnetic field taken using magnetometer sensors. The results of the work can be used in the development and implementation of missions to clean up space debris in the form of clapped-out spacecraft.

Investigating the crosstalk between chronic stress and immune cells: implications for enhanced cancer therapy

Chronic stress has a substantial influence on the tumor microenvironment (TME), leading to compromised effectiveness of anti-cancer therapies through diverse mechanisms. It disrupts vital functions of immune cells that play a critical role in anti-tumor immunity, such as the inhibition of dendritic cells (DCs) and lymphocytes, while simultaneously enhancing the activity of immune cells that support tumor growth, such as myeloid-derived suppressor cells and tumor-associated macrophages. Furthermore, chronic stress exerts a significant impact on crucial mechanisms within the TME, including angiogenesis, DNA repair, hypoxia, extracellular matrix deposition, and tumor metabolism. These alterations in the TME, induced by stress, result from the activation of the hypothalamic–pituitary–adrenal axis and sympathetic nervous system, in conjunction with epigenetic modifications. In conclusion, chronic stress significantly influences the TME and impedes the efficacy of anti-cancer treatments, underscoring the importance of targeting stress pathways to improve therapeutic results.

Assessment of the human response to acute mental stress-An overview and a multimodal study.

Numerous vital signs are reported in association with stress response assessment, but their application varies widely. This work provides an overview over methods for stress induction and strain assessment, and presents a multimodal experimental study to identify the most important vital signs for effective assessment of the response to acute mental stress. We induced acute mental stress in 65 healthy participants with the Mannheim Multicomponent Stress Test and acquired self-assessment measures (Likert scale, Self-Assessment Manikin), salivary α-amylase and cortisol concentrations as well as 60 vital signs from biosignals, such as heart rate variability parameters, QT variability parameters, skin conductance level, and breath rate. By means of statistical testing and a self-optimizing logistic regression, we identified the most important biosignal vital signs. Fifteen biosignal vital signs related to ventricular repolarization variability, blood pressure, skin conductance, and respiration showed significant results. The logistic regression converged with QT variability index, left ventricular work index, earlobe pulse arrival time, skin conductance level, rise time and number of skin conductance responses, breath rate, and breath rate variability (F1 = 0.82). Self-assessment measures indicated successful stress induction. α-amylase and cortisol showed effect sizes of -0.78 and 0.55, respectively. In summary, the hypothalamic-pituitary-adrenocortical axis and sympathetic nervous system were successfully activated. Our findings facilitate a coherent and integrative understanding of the assessment of the stress response and help to align applications and future research concerning acute mental stress.

Design of Optoelectronic Tracking Platform Driven by Ultrasonic Motor with a Novel Limiter.

A high-performance servo control system is the basis for realizing high-precision photoelectric tracking. With high position resolution and power-off self-locking, ultrasonic motors have a wide range of applications for high-precision positioning control. An optoelectronic tracking platform driven by two ultrasonic motors is proposed in this study. The shaft structure of the tracking platform is designed and modeled. The shaft structure is simplified, and a dynamic model is established to analyze the motion characteristics. The parameters of the limit mechanism are optimized based on the analysis. The shaft structure is built to verify the response characteristics of the tracking platform at different velocities. The results show that the proposed design can fully utilize the self-locking of ultrasonic motors for rapid automatic alignment of the axis system. The maximum response time is less than 55 ms. When the operating velocity is less than 70°/s, the positioning error is less than 0.055°, and the lower the speed, the smaller the positioning error.

Modern possibilities of diagnostic and therapeutic interventions for decompensated liver cirrhosis: the focus is on «gut — liver — brain». Clinical case

The relevance of the issue of management of patients with decompensated liver cirrhosis (LC) is stipulated by its medical and socio­economic importance not only in Ukraine, but worldwide due to the high prevalence of etiological factors, as well as the development of severe complications that lead to fatal consequences. Chronic alcohol intoxication is considered the most common cause of LC. The understanding of the etiopathogenetic mechanisms of liver damage and the development of complications is constantly updated, which requires the improvement of approaches to the treatment of such patients. An important role in modern diagnostic and therapeutic interventions is given to the «gut/intestinal microbiota — liver — brain» axis. Today there is evidence that intestinal microbiota indirectly affects intestinal permeability, production of nitric oxide, release of biologically active peptides from enteroendocrine cells, production of short chain fatty acids — the main metabolic product of bacteria that feed cells of the mucous membrane, affect cognitive functions and the activation of the immune system. intestinal system. Research in recent years has proven that it is the liver that takes the leading place in the «gut/intestinal microbiota — liver — brain» axis system. Today, the pathogenesis of alcoholic liver disease is also associated with the hypothesis of «leakage» of the intestine, since alcohol significantly increases its permeability. Special attention in the development of encephalopathy with an imbalance of the microbiome is paid to bacterial translocation into the submucosa due to the violation of the integrity of the tight contacts of epithelial cells, with subsequent stimulation of the release of inflammatory mediators by smooth cells and lymphocytes, which leads to the development of the inflammatory process, increased vascular permeability in the portal, hepatic and systemic networks circulation.
 The authors presented a clinical case of the use of modern possibilities of diagnostic and therapeutic interventions for decompensated liver cirrhosis of the of toxic etiology based on the global and domestic recommendations with a detailed discussion of patient care tactics.

Role of Catecholamine Hormone to Increase the Virulence of Aeromonas hydrophila

Extreme environmental conditions have been widely reported to trigger stress in exposed living organisms, and such conditions affect their homeostatics. Sress conditions lead vertebrates to release stress hormones, such as catecholamine Norepinephrin (NE) and Dopamine (Dopamine), which involve the hypothalamus-sympathetic-chromaffin (HSC) axis and the hypothalamus-pituitary-interrenal axis (HPI axis). These two axis systems produce catecholamine hormones (including adrenaline, noradrenaline, and dopamine) and corticosteroid hormones (especially cortisol). The presence of these two groups of hormones in the circulatory system of the hosts can act as a signal for pathogenic bacteria, such as Aeromonas hydrophilla commonly found in aquaculture, to start their infection process. These two types of hormones play a role in the expression of Aeromonas hydrophila genes encoding formation of flagella (allowing bacterial cells to swim rapidly to their host), pilli, toxin production, and activation of biofilm formation process. The stress conditions experienced by fishes (which triggers the secretion of catecholamine hormones) can significantly reduce the fish's immune system to function, and this will be exploited by Aeromonas hydrophila to increase its metabolic rate, growth, and virulence in such stressed fish. Specifically, catecholamine hormones can also act as a signal for the Aeromonas hydrophila to activate the ferric uptake regulator gene (fur gene), allowing this pathogenic bacterium to optimally chelate ions of iron (Fe3+) from its environment, resulting in the excessive growth of the pathogen and an increase in its pathogenicity.

New insights into the molecular basis of alcohol abstinence and relapse in alcohol-associated liver disease.

Alcohol use disorder (AUD) remains a significant public health concern, affecting around 5% of adults worldwide. Novel pathways of damage have been described during the last years, providing insight into the mechanism of injury due to alcohol misuse beyond the direct effect of ethanol byproducts on the liver parenchyma and neurobehavioral mechanisms. Thus, the gut-liver-brain axis and immune system involvement could be therapeutic targets for AUD. In particular, a change in gut microbiota composition and function, especially bile acid homeostasis, and these changes can improve after alcohol cessation. Alcohol can also directly disrupt intestinal and blood-brain barriers. Activation of the immune system can be triggered by intestinal barrier dysfunction and translocation of bacteria, pathogen-associated molecular patterns (such as lipopolysaccharide), cytokines, and damage-associated molecular patterns. These factors in turn promote liver and brain inflammation and progression of liver fibrosis. Other involved mechanisms include oxidative stress, apoptosis, autophagy, and the release of extracellular vesicles and miRNA from hepatocytes. Potential therapeutic targets include gut microbiota (probiotics and fecal microbiota transplantation), neuroinflammatory pathways, as well as neuroendocrine pathways, e.g.: the ghrelin system (ghrelin receptor blockade), incretin mimetics (GLP-1 analogs), and the mineralocorticoid receptor system (spironolactone). In addition, support with psychological and behavioral treatments is essential to address the multiple dimensions of AUD. In the future, a personalized approach considering these novel targets can contribute to significantly decreasing the alcohol-related burden of disease.

Changes in stress pathways as a possible mechanism of aerobic exercise training on brain health: a scoping review of existing studies.

Physical activity (PA) in the form of aerobic exercise (AE) preserves and improves neurocognitive function across the lifespan. However, a mechanistic understanding of the pathways by which aerobic exercise impacts brain health is still lacking, particularly with respect to stress-related pathways. One mechanistic hypothesis is that AE improves neurocognitive health in part by modifying circulating levels of stress-related hormones and signaling factors associated with the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS), as commonly measured by the biomarkers cortisol (CORT) and salivary α-amylase (sAA). Thus, this hypothesis predicts that changes in stress biomarkers, such as CORT and sAA, are possible explanatory pathways mediating the positive effects of AE on neurocognitive health. In the present review article, we provide a summary of available studies examining the possibility that exercise-induced changes to stress biomarkers could partly account for exercise-related improvements in neurocognitive health. Our review indicates that despite the intuitive appeal of this hypothesis, there is insufficient evidence available to conclude that chronic and habitual AE affects neurocognitive health by altering stress biomarker pathways. The cross-sectional nature of the majority of reviewed studies highlights the need for well-controlled studies to adequately test this hypothesis.

A Review of Antidepressant Effects and Mechanisms of Three Common Herbal Medicines: Panax ginseng, Bupleurum chinense, and Gastrodia elata.

Major depressive disorder (MDD) has been reported to affect an increasing number of individuals due to the modern lifestyle. Because of its complicated mechanisms and recurrent attacks, MDD is considered a refractory chronic disease. Although the mainstream therapy for MDD is chemical drugs, they are not a panacea for MDD because of their expensiveness, associated serious adverse reactions, and endless treatment courses. Hence, we studied three kinds of herbal medicines, namely, Panax ginseng C. A. Mey (PGM), Bupleurum chinense DC (BCD), and Gastrodia elata Blume (GEB), and reviewed the mechanisms underlying their antidepressant properties to provide a reference for the development of antidepressants and clinical medications. An extensive range of medicinal, clinical, and chemistry databases and search engines were used for our literature search. We searched the literature using certain web literature search engines, including Google Scholar, PubMed, Science Direct, CNKI (China National Knowledge Infrastructure), and Web of Science. Experimental research found that active compounds of these three medicines exhibited good antidepressant effects in vivo and in vitro. Clinical investigations revealed that single or combined treatment of these medicines improved certain depressive symptoms. Antidepressant mechanisms are summarized based on this research. The antidepressant mechanism of these three medicines includes but is not limited to ameliorating inflammation within the brain, reversing the hypothalamic-pituitary adrenal axis (HPA) system hyperfunction, inhibiting monoamine neurotransmitters reuptake, anti-neuron apoptosis and preventing neurotoxicity, and regulating depressive-related pathways such as the BDNF pathway and the PI3K/Akt/mTOR pathway.

IMMUNE SYSTEM SUSCEPTIBILITY OF DEPRESSED PATIENTS TO DENGUE VIRUS INFECTION: CASE REPORT

Introduction – Depression is a health problem that causes mortality and morbidity. The incidence of depression aged ≥ 15 years is as much as 6.1%. Another health problem is dengue hemorrhagic fever (DHF), where 71,700 confirmed cases of DHF have been reported in Indonesia as of July 2020. The study at Mayo Hospital Lahore explained that there is a correlation between DHF infection and depression. There is no study to describe susceptibility of the immune system of depressed patients to dengue virus infection in Indonesia. Methods – Presented the case of patient, female, 19 years old with initial diagnosis and management of DHF from internal medicine departement. We use a Hamilton Depression Rating Scale (HDRS) questionnaire to evaluated status mental patient. Results – The results of the patient's HDRS questionnaire showed that the patient had moderate depression. The results of the psychiatric examination showed depressive affect, anhedonia, anenergy and feeling useless with an onset 1 month before suffering from DHF. The patient was given pharmacotherapy and psychotherapy from psychiatry. Discuss – Late diagnosis and treatment of depression causes prolonged stress in the body. This condition triggers HPA axis and sympathetic nervous system which will increase levels cortisol, and increased secretion of anti-inflammatory cytokines can reduce inflammatory response to incoming pathogens, so that body will be susceptible to dengue virus infection. Management of depression at a young age with psychotherapy and pharmacotherapy use SSRI and benzodiazepines for reduce the risk of suicide. Conclusion – Late diagnosis and treatment of depression makes immune system vulnerable to pathogens or infections. Interdisciplinary collaboration is needed so that the enforcement of psychiatric cases in hospitalization becomes more accurate and for further research to be carried out on the correlation of depression with the incidence of dengue hemorrhagic fever with a different research design. Keywords: depression, DHF, HPA axis, proinflammatory cytokines, cortisol.

Optimal control theory techniques for nitrogen vacancy ensembles in single crystal diamond

Nitrogen vacancy centre ensembles are excellent candidates for quantum sensors due to their vector magnetometry capabilities, deployability at room temperature and simple optical initialization and readout. This work describes the engineering and characterization methods required to control all four principle axis systems (P.A.S.) of NV ensembles in a single crystal diamond without an applied static magnetic field. Circularly polarized microwaves enable arbitrary simultaneous control with spin-locking experiments and collective control using optimal control theory (OCT) in a (100) diamond. These techniques may be further improved and integrated to realize high-sensitivity NV-based quantum sensing devices using all four P.A.S. systems.

Positive Solutions of Operator Equations AX = B, XC = D

In this paper, using the technique of operator matrix, we consider the positive solution of the system of operator equations AX=B,XC=D in the framework of the Hilbert space; here, the ranges R(A) of A and R(C) of C are not necessarily closed. Firstly, we provide a new necessary and sufficient condition for the existence of positive solutions of AX=B and also provide a representation of positive solutions, which generalize previous conclusions. Furthermore, using the above result, a condition of equivalence for the existence of common positive solutions of AX=B,XC=D is given, as well as the general forms of positive solutions.

Cocaine and amphetamine regulated transcript (CART): a newly characterized neuropeptide in human prostate

ABSTRACT Cocaine and amphetamine regulated transcript (CART) is a somatostatin-like polypeptide. CART has been localized in the CNS, hypothalamo-pituitary-adrenocortical (HPA) axis, pancreatic islets and enteric nervous system. We investigated the cellular localization of CART in normal human prostate, benign prostatic hyperplasia, prostatic intraepithelial neoplasia and acinar adenocarcinoma. CART was assessed using immunohistochemistry (IHC) and in situ hybridization (ISH), and its gene expression was identified by RTqPCR. We found cellular expression of CART in both normal prostatic luminal secretory epithelial cells neuroendocrine cells (NEC) of both ducts and acini. The cellular appearance indicated a cycle of neuropeptide synthesis and secretion as validated by ISH/IHC concordance. RTqPCR analysis also validated the immunohistochemical data and gene expression, which both indicated low to moderate expression in prostatic tissues. CART expression also was increased in both neuroendocrine and glandular epithelial cell populations from samples of benign prostatic hyperplasia as validated by IHC, ISH and RTqPCR. CART expression was markedly diminished and, in some cases, entirely absent in tissues of prostatic intraepithelial neoplasia and adenocarcinoma. Owing to loss of CART expression in adenocarcinoma and its increase in benign prostatic hyperplasia, CART may prove to be an important prostate marker.

NOVEL ROBOTIC TECHNIQUE TO INVESTIGATE TOTAL KNEE ARTHROPLASTY STABILITY

AbstractIntroductionMid-flexion instability may cause poor outcomes following TKA. Surgical technique, patient-specific factors, and implant design could all contribute to it, with modelling and fluoroscopy data suggesting the latter may be the root cause. However, current implants all pass the preclinical stability testing standards, making it difficult to understand the effects of implant design on instability. We hypothesized that a more physiological test, analysing functional stability across the range of knee flexion-extension, could delineate the effects of design, independent of surgical technique and patient-specific factors.MethodsUsing a SIMvitro-controlled six-degree-of-freedom robot, a dynamic stability test was developed, including continuous flexion and reporting data in a trans-epicondylar axis system. 3 femoral geometries were tested: gradually reducing radius, multi-radius and single-radius, with their respective tibial inserts. 710N of compression force (body weight) was applied to the implants as they were flexed from 0–140° with three levels of anterior/posterior (AP) tibial force applied (−90N,0N,90N).ResultsWhile in static tests, the implants performed similarly, functional stability testing revealed different paths of motion and AP laxities throughout the flexion cycle. Some designs exhibited mid-flexion instability, while others did not: the multi-radius design allowed increased AP laxity as it transitioned to each arc of reduced femoral component radius; the single-radius design had low tibial bearing conformity, allowing 16mm difference in the paths of mid-flexion versus extension motion.ConclusionsPreclinical lab testing reveals functional differences between different design philosophies. Implant design impacts kinematics and mid-flexion stability, even before factoring in surgical technique and patient-specific factors.

Pathophysiological mechanisms of post-myocardial infarction depression: a narrative review.

Myocardial infarction (MI) can have significant physical and mental consequences. Depression is a prevalent psychiatric condition after MI which can reduce the quality of life and increase the mortality rates of patients. However, the connection between MI and depression has remained under-appreciated. This review examines the potential connection between depression and MI by overviewing the possible pathophysiologic mechanisms including dysregulation of the hypothalamic-pituitary-adrenal axis and autonomic nervous system, coagulation system dysfunction, inflammation, environmental factors, as well as, genetic factors. Furthermore, depression can be an adverse event of medications used for MI treatment including beta-blockers, statins, or anti-platelet agents. The need for early detection and management of depression in patients with MI is, therefore, crucial for improving their overall prognosis. Adherence to treatments and regular follow-up visits can ensure the best response to treatment.

Biological stress responses to multitasking and work interruptions: A randomized controlled trial

In the course of digitalization, new stressors are emerging. In modern working and living environments, two ubiquitous, technology-mediated stressors are multitasking demands and work interruptions. However, biological stress response patterns to multitasking and work interruptions have been sparsely investigated so far. We thus aimed to comprehensively assess biological stress response patterns to both stressors and, additionally, test whether responses differ between digital and partially non-digital settings. A controlled experimental set-up was established and humans’ biological markers of the Sympathetic Nervous System (SNS), the hypothalamic-pituitary adrenal (HPA) axis, and the immune system were assessed. N = 186 healthy participants (mean age: 23.2 ± 4.3 years, 74.7% female, body mass-index: 22.3 ± 3.1 kg/m2) took part in this pre-registered study. Each participant was randomly assigned to one of 6 experimental conditions (1 digital single-task, 3 dual-tasks [2 parallel tasks and 1 interruption], 1 multitasking, and 1 passive, control condition). Each one of the dual-tasking as well as the multitasking conditions included a non-digital sub-task, i.e., performing a task in presence of an examiner. All other conditions involved digital tasks only. Salivary alpha-amylase (sAA) levels as a marker for SNS reactivity significantly changed in work interruptions, parallel dual-tasking, and multitasking conditions. No changes were found for control conditions. Furthermore, no significant changes over time and no differences between the conditions were identified for three biological markers: cortisol as marker for HPA axis activity as well as for two immune system markers (secretory Immunoglobulin-A, C-reactive protein). A time course similar to sAA was found for perceived stress: with increases during task execution and decreases afterwards in multitasking and parallel dual-tasking. Yet, it did not change for the work interruption, passive control, and single-tasking condition. Overall, our findings show that dual- and multitasking are perceived as stressful and are associated with an activation of the SNS, but not with responses of HPA axis or immune system. This was consistent for digital as well as partially digital task demands. Our findings will also inform future research into the differential stress effects of digital and non-digital tasks to advance our understanding of biological stress response-patterns to multitasking and work interruptions. Therefore, our findings are highly relevant for understanding the long-term biological health effects of stress in modern (digitalized) environments.

Neuroprotective Effect of Phloretin in Rotenone-Induced Mice Model of Parkinson's Disease: Modulating mTOR-NRF2-p62 Mediated Autophagy-Oxidative Stress Crosstalk.

Parkinson's disease (PD) is an age-related progressive multifactorial, neurodegenerative disease. The autophagy and Keap1-Nrf2 axis system are both implicated in the oxidative-stress response, metabolic stress, and innate immunity, and their dysregulation is associated with pathogenic processes in PD. Phloretin (PLT) is a phenolic compound reported possessing anti-inflammatory and antioxidant activities. To evaluate the neuroprotective potential of PLT in PD via modulating the autophagy-antioxidant axisMethods:The neuroprotective effect of PLT was evaluated in vitro using rotenone (ROT) exposed SH-SY5Y cell line and in vivo using ROT administered C57BL/6 mice. Mice were administered with PLT (50 and 100 mg/kg, p.o.) concomitantly with ROT (1 mg/kg, i.p) for 3 weeks. Locomotive activity and anxiety behaviors were assessed using rotarod and open field tests respectively. Further apoptosis (Cytochrome-C, Bax), α-Synuclein (α-SYN), tyrosine hydroxylase (TH), antioxidant proteins (nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase-1 (HO-1) and autophagic (mTOR, Atg5,7, p62, Beclin,LC3B-I/II) protein activity were evaluated both in in vitro and in vivo. PLT improved locomotive activity and anxiety-like behavior in mice. Further PLT diminished apoptotic cell death, α-SYN expression and improved the expression of TH, antioxidant, and autophagic regulating protein. Taken together, present data deciphers that the PLT effectively improves motor and non-motor symptoms via modulating the mTOR/NRF2/p62 pathway-mediated feedback loop. Hence, PLT could emerge as a prospective disease-modifying drug for PD management.

Effect of transcutaneous vagus nerve stimulation on stress-reactive neuroendocrine measures in a sample of persons with temporal lobe epilepsy.

Dysregulation of stress-reactive neuroendocrine measures, as well as subjective stress, have been found to worsen epilepsy. Transcutaneous vagus nerve stimulation (tVNS) is a relatively new treatment option for epilepsy. We were interested in its effect on the activity of the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS) as well as subjective stress and tiredness in patients with temporal lobe epilepsy (TLE). Twenty patients (age 44 ± 11 years, 13 women) were enrolled in the study. They were free of seizures for more than 1 year. All took part in two sessions with 4 h of stimulation (tVNS vs. sham) in a randomized order. Saliva samples and subjective stress and tiredness levels were measured at five time points each session (before and after stimulation and three time points every hour in between). Data were analyzed using repeated measures analysis of variance as well as paired t-tests. There was a dampened salivary cortisol (sCort) decrease during tVNS (time × condition effect: F[2.38, 38.15] = 6.50, P = 0.002, partial η2 = 0.29). Furthermore, we detected a dampened increase in salivary flow rate during tVNS (time × condition effect: F[3.28, 55.67] = 2.82, P = 0.043, partial η2 = 0.14). There was neither a difference in overall sCort or salivary alpha-amylase (sAA) levels nor in subjective stress or tiredness levels between conditions. sAA levels at the last measurement point were slightly higher during tVNS (t(19) = 2.26, P = 0.035, d = 0.51), but this effect failed to reach significance when controlled for multiple comparisons. Our results partially support that tVNS influences the regulation of stress-reactive neuroendocrine systems (namely the HPA axis and ANS) in epilepsy. More research with larger samples is needed on the difference between short-term and repeated long-term stimulation.

Comparative Evaluation of Second-Class Lever Principle Based Single-Axis Solar Tracking System and Conventional System

This article presented the comparative study of the second-class lever principle single-axis solar tracking system (SCLPSAST) with the fixed solar axis (FSA) system. The SCLPSAST system continuously tracks the sun regardless of atmospheric conditions from sunrise to sunset. This SCLPSAST system is a cost effective and straightforward solar tracking system built with negligible operational costs. The Photovoltaic (PV) panel are directed towards the sun throughout the year without using any additional power. The main advantage is that an external motor is not required to control the solar panel. A detailed performance evaluation of the SCLPSAST system is carried out for 90 days (from Jan 2022 to Mar 2022) with the FSA system. Finally, the working functionality, efficiency improvement, and experimental consequences of the SCLPSAST system are detailed. SCLPSAST and the fixed solar system generated 8.92 kWh and 7.03 kWh, respectively, which is around 26.87% more energy than the FSA system.

Strategies of Increasing The Growth and Results Pakcoy by Modification of Media and Nutrition in The Axis System Hydroponic (Wick System)

This study seeks to determine the growth response and yield of Pakcoy plants grown in various nutrient concentrations and growing media types. This study employs a wick system and the split-plot method, which consists of the main plot, which is the Ab mix nutrition with three nutrient concentrations: 5 ml (N1), 7.5 ml (N2), and 10 ml (N3). The subplot is comprised of three kinds of planting media: Rockwool (M1), husk charcoal (M2), and cocopeat (M3). These two parameters were obtained through nine different treatment combinations. Each treatment was administered three times. The research data were analyzed with a split-plot design at a significance level of 5%. Followed by Duncan's test with a 5% significance level if there is a treatment difference. The results demonstrated a significant interaction between nutrient concentrations and the type of growing medium on the parameters of the number of leaves, plant dry weight, root fresh weight, root dry weight, root dry weight, root fresh weight, root fresh weight, root dry weight, crown fresh weight, and shoot dry weight. The results demonstrated a significant interaction between nutrient concentrations and the type of growing medium. The optimal treatment combination was found for all parameters at a nutrient concentration of 10 ml with Rockwool growing media.