Laboratory Observations Research Articles

Mock-up conception for experimentally investigate the creep phenomenon caused by the fluid–structure interaction in a rod bundle

Pressurized water reactors (PWRs) are employed worldwide and continue to expand in capacity. They require thorough investigation, particularly concerning their safety and operational efficiency. To ensure these factors, comprehensive research into their various components and an understanding of the diverse phenomena they experience within a PWR are imperative. These phenomena can be of mechanical, thermal, hydraulic, or neutronic nature. Among these components, fuel assemblies (FAs) hold a main role in PWRs. The intricate interplay of these physical factors results in the modification of FAs geometry, specifically permanent elongation and lateral deformations referred to as irradiation creep. The earliest reported occurrence of these deformations dates back to 1994 in Ringhals reactors, where various FAs exhibited distinct deformations (Andersson et al., 2005). Given that these phenomena occur over a time span of months to years in metallic materials, conducting investigations within the confines of a typical laboratory observation period becomes impractical. Consequently, this project proposes an alternative experimental methodology to overcome this challenge, thus gaining a deeper understanding of the fluency phenomenology in FAs behavior. This methodology consists on the design of a reduced-scale test section, capable of replicating the fluid–structure interaction (FSI) responsible for creep, the creation of spacer grids through 3D printing technology, and selection of the appropriate material for the fuel rods (FRs), with an emphasis on macroscopic coupling effects, rather than focusing into the micro-structural response of the material. To experimentally observe the deformation on the FAs, cameras were used to capture images through the time during the test, to catch the displacement of the FRs. The first results showed the mock-up was able to reproduce the FSI causing the creep on the FAs, it was possible to capture the displacement evolution along time, and to observe different types of deformation, thus, it helps to understand the phenomenon. Further tests and investigations using laser doppler velocimetry (LDV) technique to analyze the flow will be held, to a better comprehension of these burden.

Caregiver encouragement to act on objects is related with crawling infants' receptive language.

The progression from crawling to walking in infancy is associated with changes in infant language development. One possible explanation for such change is the infant's language environment. Prior research indicates that caregivers use more action directives with walking infants compared to crawling infants, but the relations of such parental speech with infant vocabulary is unknown. Here, we present findings from day-long home audio recordings (Study 1) and laboratory observations (Study 2) of same-aged crawling and walking infants to explore how caregiver language, specifically action directives, were associated with parent reported infant vocabulary size. Findings in both studies indicated that caregiver action directives were associated with crawling, but not walking infants' receptive vocabulary sizes. Specifically, action directives about objects occurring when the infant and caregiver were not jointly engaged were associated with higher receptive vocabulary scores for crawling infants, but no such pattern was found for walking infants. The replication of results in distinct samples with different research methodologies strengthens the findings. Taken together, these studies demonstrate that caregiver social engagement specific to infant motoric development is related with infant language learning.

A case of hemolytic-uremic syndrome that developed in a 5-year-old child due to acute intestinal infection with hemocolitis

Purpose: to demonstrate a case of hemolytic-uremic syndrome (HUS) in a 5-year-old child associated with an acute intestinal infection of unknown etiology, occurring with hemocolitis. Results. During clinical and laboratory observation, edematous syndrome, oligoanuria, severe microangiopathic hemolytic anemia (decrease in hemoglobin, haptoglobin, increase in Lactate dehydrogenase), thrombocytopenia, consumption coagulopathy, hyperazotemia, acute kidney injury (AKI) according to KDIGO grade 2 (increase in serum creatinine more than 2 times) developed. As part of complex therapy with balanced crystalloid solutions with stimulation of diuresis, it was possible to achieve rapid restoration of diuresis on the 2nd day of hospital stay without the use of renal replacement therapy; he also received antibiotics, anticoagulants, transfusion of fresh frozen plasma and red blood cell suspension. Hyperazotemia was relieved within 5 days, as was thrombocytopenia. The follow-up recovery of renal function showed.

Summary of Experiments and Influencing Factors of Sediment Settling Velocity in Still Water

Sediment deposition significantly impacts soil erosion processes, consequently influencing the geographical morphology and surrounding environments of reservoirs and estuaries. Given the intricate nature of sediment deposition, it is imperative to consolidate and analyze existing research findings. Presently, studies on sediment settling velocity primarily employ theoretical, laboratory, and field experimentation methods. Theoretical approaches, rooted in mechanics, examine the various forces acting on sediment particles in water to derive settling velocity equations. However, they often overlook external factors like temperature, salinity, organic matter, and pH. Although laboratory experiments scrutinize the influence of these external factors on sedimentation velocity, sediment settling is not solely influenced by individual factors but rather by their collective interplay. Field observations offer the most accurate depiction of sediment deposition rates. However, the equipment used in such experiments may disrupt the natural sedimentation process and damage flocs. Moreover, measurements of sediment particle size from different instruments yield varied results. Additionally, this paper synthesizes the impact of suspended sediment concentration, particle size, shape, temperature, salinity, and organic matter on sediment settling velocity. Future research should focus on innovating new laboratory observation methods for sediment settling velocity and utilizing advanced scientific and technological tools for on-site measurements to provide valuable insights for further investigation into sediment settling velocity.

Evaluation of Local Common Bean (Phaseolus vulgaris L.) Genotypes for Resistance to Fungal Diseases in the Bimodal-rainfall Forest Zone of Cameroon

The general objective of the present study was to evaluate the susceptibility to fungal diseases of some bean collections in the bimodal rainfall forest zone of Cameroon. To this end, 12 bean collections from Foumbot were grown at the University of Yaoundé I in a completely randomized block design without phytosanitary treatments. Symptoms identified on the leaves of diseased plants were used to characterize the fungal agents in the laboratory using an identification key. Incidence and severity were assessed, as well as the number of pods and seeds in plants under fungal pressure. Following the evolution of symptoms, all collections showed fungal disease attacks at different rates. Macroscopic and microscopic laboratory observations identified Sclerotinia sclerotiorum, Uromices appendiculatus and Fusarium solani as the fungal agents responsible for these symptoms. The incidence of disease caused by F. solani was lower in the NJBPRNV (16.67%) and NJBV (22.22%) collections, as was severity (3.33% and 4.44%). On the other hand, the LGRTE (47.06%) and GGRBE (44.44%) LGRV (43.75%) collections showed high incidences of disease caused by S. sclerotiorum, U. appendiculatus and F. solani respectively. Considering the number of seeds, the KPGPV (403.2 seeds) and KPGPTV (350.4 seeds) collections recorded the highest number of seeds, compared with the GGRBE (15.93 seeds); LGRTE (23.87 seeds); GGRBTE (25.53 seeds); LGRV (42.4 seeds) and GGRTE (52.2 seeds) collections. However, the NJBPRNV collection requires special attention in varietal creation, given its greater resistance to the fungal diseases identified.

Optimizing healthy snacks for diabetics: Study of fiber and starch digestibility of glucomannan-modified Growol cookies

Diabetes mellitus (DM) is an emergency health problem in the 21st century. High dietary fiber and resistant starch foods with low starch digestibility are solutions for DM. The addition of glucomannan to food can optimize the levels of dietary fiber, resistant starch, and starch digestibility. This study aimed to examine the optimization of dietary fiber, resistant starch, and starch digestibility in Growol cookies supplemented with glucomannan. Laboratory observations were conducted at the Universitas Respati Yogyakarta and Chemmix Pratama Yogyakarta Laboratory between July and September 2023. Cookies consisted of cookies A (negative control), B (positive control), C (modified 10-gram inulin), D (modified glucomannan 3%), and E (modified glucomannan 7%). Dietary fiber and resistant starch analyses were performed using the multi-enzyme method. Starch digestibility was determined by comparing the starch content obtained using the enzymatic method with that obtained using the acid hydrolysis method. Statistical analyses were performed using ANOVA and Kruskal-Wallis tests. There were differences in dietary fiber and resistant starch among the variants (p<0,001) with the highest being cookies E. There was no difference in starch digestibility between the variants (p=0,104) with the lowest being cookies E. In conclusion, glucomannan addition can optimize dietary fiber and resistant starch levels, as well as the starch digestibility of Growol cookies as a healthy snack for diabetics.

First observation of the beetle Sericoderus lateralis consuming Cladosporium fulvum in a greenhouse tomato: potential for biological protection or risk to the crop?

For the first time, the mycophagous beetle Sericoderus lateralis (Gyllenhal, 1827) was documented feeding on tomato leaf mold ( Cladosporium fulvum Cooke, 1878) tissues. The phenomenon was observed during the years 2022 and 2023 in a hydroponic tomato greenhouse situated near the Czech-Polish border within the cadastre of Dolní Lutyně municipality in Czechia. Greenhouse and laboratory observations confirmed that adult and larvae feeding activity led to a reduction in tomato leaf mold lesions. In addition, there was a positive correlation between tomato leaf mold disease progression and increased populations of S. lateralis in the tomato crop. Petri dish observations confirmed egg laying occurred on a diet of tomato leaf mold. Further research is warranted to discern whether S. lateralis is a potential biological control agent for tomato leaf mold or if it acts to facilitate the spread of the disease by acting as a spore vector.

Insights from underground laboratory observations: attenuation-induced suppression of electromagnetic noise

Insights from underground laboratory observations: attenuation-induced suppression of electromagnetic noise

Laboratory observation of nonlinear wave shapes due to spatial varying opposing currents

Physical experiments were conducted to examine the influence of adverse currents on the propagation of shallower water waves and their impact on the evolution of nonlinear wave shapes. Irregular waves, characterized by varying initial peak periods and amplitudes, were generated in a physical wave flume equipped with a bottom slope of 1/20. Three groups of spatially varying opposing currents were generated in the flume and interacted with the aforementioned wave trains. Experimental results confirm that strong opposing currents can significantly intensify local wave nonlinearity, thereby further influencing the deformation characteristics of waves. In contrast, a weak opposing current (without wave-blocking) has a negligible effect. Bicoherence analysis revealed that the degree of phase coupling among triads of waves increased with an elevated current velocity before wave-blocking. Nevertheless, during partial wave-blocking, the degree of phase coupling was seemingly weakened by an increase in opposing current. Moreover, the influence of a co-existing current in the formation of extreme waves was recognized. The study confirms that adverse currents notably affect extreme wave steepness and extreme wave skewness, with a negligible impact on extreme wave asymmetry. As a result, empirical formulas modified by current effects are presented, describing certain key nonlinear wave shapes as functions of the local Ursell number.

Laboratory observation of electron energy distribution near three-dimensional magnetic nulls

The acceleration of electrons near three-dimensional (3D) magnetic nulls is crucial to the energy conversion mechanism in the 3D magnetic reconnection process. To explore electron acceleration in a 3D magnetic null topology, we constructed a pair of 3D magnetic nulls in the PKU Plasma Test (PPT) device and observed acceleration of electrons near magnetic nulls. This study measured the plasma floating potential and ion density profiles around the 3D magnetic null. The potential wells near nulls may be related to the energy variations of electrons, so we measured the electron distribution functions (EDFs) at different spatial positions. The axial variation of EDF shows that the electrons deviate from the Maxwell distribution near magnetic nulls. With scanning probes that can directionally measure and theoretically analyze based on curve fitting, the variations of EDFs are linked to the changes of plasma potential under 3D magnetic null topology. The kinetic energy of electrons accelerated by the electric field is 6 eV ( ) and the scale of the region where accelerating electrons exist is in the order of serval electron skin depths.

GAMBARAN KADAR PARASETAMOL DALAM URINE PENGONSUMSI JAMU

Herbal medicine can provide significant health benefits, both for the prevention and treatment of disease, as well as in terms of maintaining fitness and beauty and increasing body stamina without causing side effects. Therefore, the composition of herbal medicine must not contain medicinal chemicals (BKO). This study aims to determine the levels of paracetamol in the urine of herbal medicine users. This type of research is laboratory observation in nature where the samples used in this research were 10 urine samples using a purposive sampling technique and the sample examination method used was the O-cressol method. Based on the results of research conducted on 10 urine samples of herbal medicine users, negative results were obtained with no blue color forming. Thus, it can be concluded that 10 urine samples showed negative results, namely that there was no paracetamol in the urine of herbal medicine users.

DETEKSI CEMARAN Escherichia coli PADA SAUS SAMBAL JAJANAN

AFood is a basic need for living beings whose function is as a source of energy used for activities and growth and development. Food safety is needed to prevent food from possible biological, chemical, and other contaminants that can interfere with, harm, and endanger human health and do not conflict with the religion, beliefs, and culture of the community so that it is safe for consumption. Escherichia coli is considered an indicator of water and food pollution and also shows a sign of poor sanitation. The quality of jalangkote sauce is required to meet the requirements set out in the Regulation of the Minister of Health of the Republic of Indonesia Number 1096/Menkes/Per/VI/2011 with the number of Escherichia coli in food showing zero (negative), which means there should not be a single colony of Escherichia coli in the food. This study aims to identify Escherichia coli in jalangkote sauce samples sold in Makassar city. The type of research used is laboratory observation with a total of 7 jalangkote sauce samples. Based on identification on Eosin Methylen Blue Agar (EMBA) media, there are no metallic green colonies. It can be concluded that there is no contamination of Escherichia coli bacteria.

Potential bottom‐up control of Metamasius callizona in Florida, USA

AbstractMetamasius callizona (Chevrolat) (Coleoptera: Curculionidae) is an invasive weevil destroying Tillandsia utriculata L. (Bromeliaceae) populations in Florida, USA. A T. utriculata population in Belize coexists with M. callizona without adverse effects. Tillandsia utriculata and M. callizona from Belize and Florida were studied in the laboratory to determine how Belize T. utriculata can coexist with Belize M. callizona, using Florida and Belize T. utriculata, as well as pineapple, Ananas comosus (L.) Merr. (Bromeliaceae), as host plants. Florida M. callizona on pineapple leaves produced more eggs per female per day and had a shorter developmental time and pupation period, as well as a smaller adult width, than Belize M. callizona. Florida and Belize weevils did not differ significantly in rates of egg hatch, pupation, and adult emergence. Florida M. callizona laid similar numbers of eggs per day on Florida and Belize T. utriculata. Egg hatch rates were similar on pineapple and Florida and Belize T. utriculata. Pupation rates were similar on pineapple and Florida T. utriculata leaves; no larvae on Belize T. utriculata attained fourth instar. Field and laboratory observations revealed that Belize and Florida M. callizona mined Belize T. utriculata without destroying the meristem, allowing plants to survive, but Belize M. callizona destroyed the core of pineapple tops. Soluble solids were greatest in pineapple and least in Belize T. utriculata. Leaf toughness was greatest in pineapple and least in Florida T. utriculata. Metamasius callizona biology and behavior and T. utriculata plant characteristics may drive the severity of weevil damage on populations of T. utriculata. The discovery of a T. utriculata population in Belize coexisting with M. callizona offers a possible way to control M. callizona in Florida.

Skin and hard surface disinfection against Candida auris - What we know today.

Candida auris has emerged as a global healthcare threat, displaying resistance to important healthcare antifungal therapies. Infection prevention and control protocols have become paramount in reducing transmission of C. auris in healthcare, of which cleaning and disinfection plays an important role. Candida albicans is used as a surrogate yeast for yeasticidal claims of disinfection products, but reports have been made that sensitivity to disinfectants by C. auris differs from its surrogate. In this review, we aimed to compile the information reported for products used for skin and hard surface disinfection against C. auris in its planktonic or biofilm form. A comparison was made with other Candida species, and information were gathered from laboratory studies and observations made in healthcare settings.

Gambaran Telur Soil Transmitted Helminth (STH) Pada Anak-anak Yang Terindikasi Stunting Menggunakan Metode Natif

Soil-transmitted Helminth (STH) worm eggs are a type of intestinal parasite that can cause infections in humans, especially children. This parasitic infection can cause stunting, which can have a negative impact on health. This study aims to determine the description of soil-transmitted helminth (STH) eggs in children with indications of stunting. This research was carried out using laboratory observations. The object of this research was to collect feces using a random sampling technique with a direct (native) method. Based on the research that has been carried out, of the 16 feces samples, 9 positive samples were found to have soil-transmitted helminth (STH) worm eggs consisting of 7 Ascaris lumbricoides egg samples, 2 Trichuris trichiura egg samples, and 7 negative samples. It follows that one possible cause of childhood stunting could be the egg infection caused by soil-transmitted helminth (STH) worms.

Laboratory observation of shear stress recovery in rock joints considering joint compaction and dilatancy

Understanding the shear stress recovery mechanism during the stick-slip motion is a fundamental requirement for predicting the sliding behavior of rock joints. In this study, slide-hold-slide (SHS) type direct shear experiments under constant normal stress are performed on granite joints with significant roughness components to investigate the effects of compaction and dilation on the shear stress recovery. The shear stress recovery of rock joints is contributed by the growth of the contact area induced by the compaction during the hold period and the enhancement of dilation work during the re-shear process. The contact area reaches the maximum value under relatively low normal stress after the long hold period. Then, the dilation gradually contributes to the shear stress recovery because the welded asperities or grains are assembled, and the slide needs to ride over these bonded areas. The surface roughness plays a significant role in the shear stress recovery since the initial aperture and asperity morphology affect the compaction and dilation. The greater magnitude of shear stress recovery observed on rougher surfaces can be attributed to the effective normal closure during the hold period and significant dilation after the long hold periods.

Excitation of cylindrical and spherical precursor solitons in a flowing dusty plasma: Experimental and simulation studies

We report the first laboratory observation of precursor cylindrical and spherical solitons excited in a flowing dusty plasma. The experiments are carried out in an inverted Π-shaped dusty plasma experimental device in which a dust cloud is created in a background Argon plasma using micrometer-sized Kaolin particles. Using the single gas injection technique, the dust fluid is made to flow in a controlled manner over a cylindrical (or a spherical) charged object for a range of flow velocities. When the flow velocity exceeds a critical value, cylindrical (or spherical) solitons are excited, which, in the frame of the dust fluid, travel in the upstream direction, while wake structures propagate in the downstream direction. Unlike one-dimensional solitons, the amplitudes of these higher dimensional solitons decrease with time (and hence distance) while maintaining constancy of the product of their amplitudes with the square of their widths. The spherical solitons decay at a rate faster than the cylindrical soliton. It is also found that their amplitudes and velocities increase, and their widths decrease with an increase in the dust fluid velocity. Furthermore, the radii of curvature of the cylindrical and spherical solitons decrease with an increase in the dust fluid flow velocity. A 3D molecular dynamics simulation of the excitation phenomenon provides a good theoretical support to the experimental observations.

Laboratory Observation of the Buffering Effect of Aragonite Dissolution at the Seafloor

AbstractCarbon dioxide entering and acidifying the ocean can be neutralized by the dissolution of calcium carbonate, which is mainly found in two mineral forms. Calcite is the more stable form and is often found in deep‐sea sediments, whilst aragonite is more soluble and therefore rarely preserved. Recent research shows aragonite may account for a much larger portion of marine calcium carbonate export to the ocean interior via the biological pump than previously thought, and that aragonite does reach the deep sea and seafloor despite rarely being buried. If aragonite is present and dissolving at the seafloor it will raise local pH and calcium and carbonate concentrations, potentially enough to inhibit calcite dissolution, representing a deep‐sea, carbonate version of galvanization. Here, we test this hypothesis by simulating aragonite dissolution at the sediment‐water interface in the laboratory and measuring its effects on pH using microsensors. We show that the addition of aragonite to calcite sediment, overlain by seawater undersaturated with respect to both minerals, results in an unchanged alkalinity flux out of the dissolving sediment, suggesting a decrease the net dissolution rate of calcite. In combination with a diagenetic model, we show that aragonite dissolution can suppress calcite dissolution in the top millimeters of the seabed, locally leading to calcite precipitation within 1 day. Future research efforts should quantify this galvanization effect in situ, as this process may represent an important component of the marine carbon cycle, assigning a key role to aragonite producers in controlling ocean alkalinity and preserving climatic archives.

Clinical parameters for the early detection of complications in patients with blunt hepatic and/or splenic injury undergoing non-operative management.

Complications arising during non-operative management (NOM) of blunt hepatic and/or splenic trauma, particularly in cases of severe injury, are associated with significant morbidity and mortality. Abdominal computed tomography (CT) is the gold standard for the initial detection of complications during NOM. Although many institutions advocate routine in-hospital follow-up scans to improve success rates, others recommend a more selective approach. The use of follow-up CT remains a subject of ongoing debate, with no validated guidelines available regarding the timing, effectiveness, or intervals of follow-up imaging. We aimed to identify the clinical parameters for the early detection of complications in patients with blunt hepatic and/or splenic injury undergoing NOM. This retrospective cohort study included patients with blunt hepatic and/or splenic trauma treated at Songklanagarind Hospital, a level 1 trauma center, from 2013 to 2022. We assessed all patients indicated for non-operative management and examined their clinical parameters and complications. Of 542 patients with blunt hepatic and/or splenic injuries, 315 (58%) were managed non-operatively. High-grade hepatic injuries were significantly associated with complications, as determined through a multivariate logistic regression analysis after adjusting for factors such as contrast blush findings, age, sex, and injury severity score (ISS) (adjusted OR = 7.69, 95% CI 1.59-37.13; p = 0.011). Among the patients with complications (n = 27), 17 (63%) successfully underwent non-operative management. Notably, eight patients presented with clinical symptoms prior to the diagnosis of complications, while only two patients had no clinical symptoms before the diagnosis. Tachycardia, abdominal pain, decreased hematocrit levels, and fever were significant indicators of complications (p < 0.05). Routine CT to detect complications may not be necessary in patients with asymptomatic low-grade blunt hepatic injuries. By contrast, in those with isolated blunt hepatic injuries that are managed non-operatively, high-grade injuries, the presence of a contrast blush on initial imaging, and the patient's age may warrant consideration for routine follow-up CT scans. Clinical symptoms and laboratory observations during NOM, such as tachycardia, abdominal pain, decreased hematocrit levels, and fever, are significantly associated with complications. These symptoms necessitate further management, regardless of the initial injury severity, in patients with blunt hepatic and/or splenic injuries undergoing NOM.

The Effects of Administration of Total Glucoside Peony (TGP) on Autoimmune Diseases: Clinical and Laboratory Observations as Preliminary Research

Autoimmune diseases cause the host immune system to produce antibodies that attack its own tissues due to an exaggerated immune response to the body's own tissues and materials simultaneously. Conventional treatment of autoimmune diseases are NSAIDs, glucocorticoids, and immunosuppressants that have not met the satisfaction of autoimmune therapy. The purpose of this study was to identify the usefulness and side effects of TGP against autoimmune diseases as a complementary therapy to low-dose basic therapy. This research method is an original research and intervention. This is an initial study with an analytical observational approach. The design is a 'single-group pretest-posttest design'. This research was conducted at RSUP Prof. dr. R.D Kandou and other private hospitals in Manado and Tomohon. The subjects of the study were autoimmune patients. The addition of TGP in this study did not have significant side effects on Hb, leukocytes, liver and kidney function, and the gastrointestinal tract. From this study, it can be concluded that there are clinically significant improvements in RA, Graves, Hashimoto, and Psoriasis, significant laboratory improvements in CRP and LED levels for all autoimmune patients, and insignificant laboratory improvements in anti-TPO, TSH, and FT4 levels for Graves and Hashimoto. In Aplastic Anemia, there is a significant improvement in the number of leukocytes and platelets. There are no side effects on the gastrointestinal tract, Hb, leukocytes, platelets, liver function, and kidneys.