Small End Research Articles

Foragers Downstream of Mapungubwe: the Cultural Sequence and Chronology of Skirbeek Shelter, South Africa

ABSTRACT In recent decades, interest in the Later Stone Age of the Mapungubwe region has increased. Here, we present the results of an investigation from a shelter downstream from Mapungubwe called Skirbeek. The shelter is in a sandstone koppie (tor) adjacent to another that was occupied in the 19th century a.d. by a Venda community. Radiocarbon results show three primary occupation phases in the mid-Holocene, final millennium b.c., and mid–late 2nd millennium a.d. The most intensely occupied phase was before ca. a.d. 750 prior to the arrival of herders, possibly, and farmers. There are several continuities and other discontinuities between these periods. Quartz dominates assemblages in each period, as do small end scrapers, but artifact and faunal frequencies vary. We compare these findings to those made in the Mapungubwe region and argue that Skirbeek represents a similar Later Stone Age phase. More generally, it appears largely consistent with Wilton assemblages defined in South Africa’s Cape zone rather than the Amadzimba and Bambata (or Ceramic Matopan) Industries found in Zimbabwe.

ThP6.18 - 2 week wait referrals for suspected colorectal cancer in patients more than 85 years old. How many actually end up on the operating table?

Abstract Aims To assess the outcomes of 2 week wait referrals for patients > 85 years old for suspected colorectal cancer in a large university hospital Methods Retrospective review of records of patients >85years old referred on the pathway between September to November 2023. Outcomes assessed were the number of patients that underwent investigation, cancers detected and whether they ended up having surgery. Results 211 patients were referred. 43 were not investigated (20.4%), 95 had CT-colons (45%), 37 had CT-abdomen, 25 had flexible-sigmoidoscopy, 15 had CT Chest-abdomen-pelvis, only 10 had a colonoscopy (4.7%). 13 colorectal cancers were diagnosed (6.2%). Out of these only 3 agreed and were fit to proceed with surgery, 7 refused surgery and 2 were undecided while 1 passed away 2 weeks after the diagnosis was made. 5 incidental extracolonic cancers were diagnosed (2 pancreatic, 2 renal and 1 lung, 2 of which were metastatic) All the diagnosed colorectal cancers were FIT positive (100% sensitivity). 7 had no FIT test done and 14 were FIT negative. Conclusion The incidence of colorectal cancers in this group of patients is relatively small and most end up being not fit for investigation or surgery or refusing it themselves even when cancer is diagnosed. These patients should still have the right to be investigated and treated if they wish to but a pragmatic discussion needs to be made with them by the referring clinician before a referral is made as well as making use of the very high sensitivity of FIT testing to ensure optimal use is made of the limited resources available in our already stretched system.

The loosening mechanism of tin-bronze bushing assembled by interference at connecting rod small end of heavy-duty diesel engines

The loosening mechanism of tin-bronze bushing assembled by interference at connecting rod small end of heavy-duty diesel engines

Optimization of Oil Bores on Connecting Rod Small End to Prevent Bushing Failures at Maximum Speed

Abstract The bushing of connecting rod small end is one of the most prone components to failure in diesel engines. According to previous study, the oil flowrate and storage of small end bearing with splash lubrication are both minimal at maximum speed. Thus the optimization of oil bores was performed using a model based on smooth particle hydrodynamics. By adjusting the angle between the axes of two oil bores to 90°, the oil flowrate and storage increase from 0.036 mL/s and 0.04 mL to 0.094 mL/s and 0.045 mL, respectively. A semicolumn baffle above oil bore away from piston cooling nozzle further increases them to 3.564 mL/s and 0.8 mL. The optimization greatly enhances the cooling intensity and oil supply stability of small end bearing, conducing to prevent bushing failures.

Multi-scale modeling of fog harvesting using thin-fiber grids – Towards new design rubrics

Fog collectors with fibers thinner than 1 mm harvest fog droplets more effectively at a low airflow velocity around 1 m s-1 than thicker fibers. However, existing models and design rubrics are restricted to thick fibers at higher velocity. This paper reports a multi-scale numerical model for fog harvesting at airflow velocity of 1 m s-1 using thin-fiber grids with different fiber spacing and diameter. The numerical model can simulate fog harvesting at two extreme length scales that are comparable to collector scale at the large end and fiber scale at the small end. The results confirm two new and important effects of fiber grid geometries on water collection efficiency, which are not included in existing theories and design rubrics. First, dense thin-fiber grids negatively influence the collection efficiency because of wall effect caused by viscous boundary layers. Second, the sparse thin-fiber grids can benefit from isolated clogging waterdrops and maintain relatively high efficiency when clogging blocks multiple grid openings. The two identified effects are then included to develop a new performance map for fog collectors, thereby shaping new design rubrics for fog harvesting. This work extends the existing theories of fog harvesting and sheds light on the design of novel fog collectors.

Flutter in functionally graded conical shell under follower force

Truncated conical shells are essential components of rocket booster nozzles and thrust vector control (TVC) systems for the propulsion of multi-stage launch vehicles. The TVCs assist the ascent of launch vehicles by directing the resultant thrust from the boosters, acting as a follower force that might trigger instability. Previous studies on the instability of aerospace structures have mostly focused on beams, plates, and cylindrical shells. This study analyses a truncated conical shell under a follower force of constant magnitude, considering thickness-wise gradation of material properties employed for thermal management. The governing equations are derived following Hamilton's principle, considering first-order shear deformation theory, and solved using the finite element method. Clamped and free boundaries are assumed at the small and large ends. The influence of mass and stiffness proportional damping is considered. Although strong flutter appears as the dominant instability mode, instances of erratic weak instabilities are also observed for undamped and lightly damped cases. Damping enhances stability, but its effect becomes saturated. The flutter loads are presented for varying non-dimensional parameters, characterizing the shell geometry and material properties.

How does a small firm end up with a more expensive loan guarantee when a cheaper and safer one was on offer? The intriguing case of two UK Covid-19 guarantee schemes

Most countries introduced loan guarantee schemes in the Covid-19 pandemic, and the UK offered two schemes. The BBL scheme had a cap of £50,000, a 100 % guarantee, and a fixed interest rate of 2.5 %. The CBILS scheme had a cap of £5 m, an 80 % guarantee and lenders set interest rates. We exploit a behavioural anomaly that led to 9,989 firms taking a CBILS loan for a cash amount below the BBL loan cap. Larger and older firms were more likely to be in this loan class and this is caused by lender sorting of firms by risk.

Effectiveness of the Specific Mobility Exercises on Pain Intensity and Quality of Life Among Stoma Patients: A Quasi-experimental Study.

An intestinal stoma is a surgically created artificial opening in the abdominal wall that helps the largeor small intestine end to divert the faecal matter for stoma patients with an underlying condition of inflammatory bowel disease and colorectal cancer.When a stoma is formed following surgery, one of the difficulties stoma patients confront has been identified as prolonged immobilization, which can eventually result in muscle inactivity that results due to their illness. Patients with stoma often experience an increase in pain and a decrease in quality of life. Patients can be mobilized and their muscles can be activated with the help of an early intervention calledspecific mobility exercises. The present study aimed to explore thespecific mobility exercises that reduce pain and improve quality of life among stoma patients. This quasi-experimental study involved 21 patients who underwent stoma surgery and were selected according to the inclusion and exclusion criteria. The experimental procedures were explained to all the patientsand their written informed consent was obtained. The patients performed specific mobility exercises for 30 minutes per day. Treatment was given for four weeks every day after three to four days of stoma surgery. The patient's pain and quality of life were assessed using the Numerical Pain Rating Scale and the Stoma-Quality of Life (QoL) Questionnaire andpre-test and post-test values were recorded before and after theexercises. The data were tabulated and evaluated. The findings suggest that specific mobility exercises following four weeks of intervention have a significant effect (p< 0.001) in reducing pain except inyoung adult stoma patients as they were found to be anxious and depressed, which was reflected in the findings as not statistically significant for pain on the NPRS (t(1) = 7, p > 0.001). However, it has been demonstrated that these specific mobility exercises have a significant effect (p< 0.001) in improving the quality of life among all stoma patients. The study evidenced that four weeks of specific mobility exercises in line with general medical treatment showed a significantreduction in pain and an improvement in quality of life among stoma patients. However, it should be noted that in the study, the majority of stoma patients were male and there were only a few patients with inflammatory bowel disease, which can limit the study findings. Future studies have to focus on equally distributing gender and conditions by emphasizing the importance of randomizing patients into the experimental and control groups and involving a combination of other exercises in rehabilitation for patients following stoma surgery.

Organophosphate Ester Flame Retardants and Plasticizers in Relation to Fetal Growth in the LIFECODES Fetal Growth Study.

Organophosphate esters (OPEs), used ubiquitously as flame retardants and plasticizers in consumer products, are suspected of having developmental toxicity. Our study aimed to estimate associations between prenatal exposure to OPEs and fetal growth, including both ultrasound (head circumference, abdominal circumference, femur length, and estimated fetal weight) and delivery [birth weight z-score, small-for-gestational age (SGA), and large-for-gestational age (LGA)] measures of growth. In the LIFECODES Fetal Growth Study (2008-2018), an enriched case-cohort of 900 babies born at the small and large ends of the growth spectrum, we quantified OPE biomarkers in three urine samples per pregnant participant and abstracted ultrasound and delivery measures of fetal growth from medical records. We estimated associations between pregnancy-averaged log-transformed OPE biomarkers and repeated ultrasound measures of fetal growth using linear mixed-effects models, and delivery measures of fetal growth using linear (birth weight) and logistic (SGA and LGA) regression models. Most OPE biomarkers were positively associated with at least one ultrasound measure of fetal growth, but associations with delivery measures were largely null. For example, an interquartile range (IQR; ) increase in bis(2-chloroethyl) phosphate concentration was associated with larger z-scores in head circumference [mean difference (difference): 0.09; 95% confidence interval (CI): 0.01, 0.17], abdominal circumference (difference: 0.10; 95% CI: 0.02, 0.18), femur length (difference: 0.11; 95% CI: 0.03, 0.19), and estimated fetal weight (difference: 0.13; 95% CI: 0.04, 0.22) but not birth weight (difference: 0.04; 95% CI: , 0.17). At delivery, an IQR () increase in diphenyl phosphate (DPHP) concentration was associated with an SGA birth (odds ratio: 1.46; 95% CI: 1.10, 1.94). In a large prospective cohort, gestational OPE exposures were associated with larger fetal size during pregnancy, but associations at delivery were null. DPHP concentrations were associated with heightened risk of an SGA birth. These findings suggest that OPE exposure may affect fetal development. https://doi.org/10.1289/EHP14647.

CCN Activation and Droplet Growth in Pi Chamber Simulations with Lagrangian Particle–Based Microphysics

Abstract Numerical simulations of turbulent moist Rayleigh–Bénard convection driving CCN activation and droplet growth in the laboratory Pi chamber are discussed. Supersaturation fluctuations come from isobaric mixing of warm and humid air rising from the lower boundary with colder air featuring lower water vapor concentrations descending from the upper boundary. Lagrangian particle–based microphysics is used to represent the growth of haze CCN and cloud droplets with kinetic, solute, and surface tension effects included. Dry CCN spectra in the range between 2- and 200-nm radii from field observations are considered. Increasing the total CCN concentration from pristine to polluted conditions results in an increase in the droplet concentration and reduction in the mean droplet radius and spectral width. These are in agreement with Pi chamber observations and numerical simulations, as well as with numerous past studies of CCN cloud-base activation in natural clouds. The key result is that a relatively small fraction of the available CCN is activated in the Pi chamber fluctuating supersaturations, from about a half in the pristine case to only a 10th in the polluted case. The activation fraction as a function of the dry CCN radius is similar in all simulations, close to zero at the CCN small end, increasing to a maximum at CCN radius around 50 nm, and decreasing to close to zero at the large CCN end. This is explained as too small supersaturations to activate small CCN as in natural clouds and insufficient time to allow large CCN reaching the critical radius. Significance Statement Impact of turbulence on the formation and growth of cloud droplets is an important cloud physics problem. Laboratory experiments in the Michigan Technological University cloud chamber provide key insights into this problem. Numerical simulations of cloud chamber processes discussed in this paper complement laboratory experiments by providing insights difficult or impossible to obtain in the laboratory. The study contrasts the formation and growth of cloud droplets in the laboratory cloud chamber with processes taking place in natural clouds. The differences documented in this paper pose questions concerning the impact of turbulence on the formation and growth of cloud droplets as a result of interactions of clouds with their environment.

Jupiter Co-Orbital Comet P/2023 V6 (PANSTARRS): Orbital History and Modern Activity State

The discovery of the transient Jupiter co-orbital comet P/2019 LD2 (ATLAS) drew significant interest. Not only will LD2 transition between being a Centaur and a Jupiter-family comet (JFC) in 2063, the first time this process can be observed as it happens, it is also very active for its large heliocentric distance. We present observations and orbital integrations of the newly discovered transient Jupiter co-orbital comet P/2023 V6 (PANSTARRS), the second such object known. Despite similar modern orbits, V6 is significantly (15×) less active than LD2 and most JFCs as determined via Af ρ measurements at the same R H . We find that V6 is co-orbital between 2020 and 2044, twice the duration of LD2, but it will not become a JFC soon. We interpret these differences in activity as evolutionary, with V6 having lost a significant fraction of its near-surface ice compared to LD2 by previously being warmer. While V6's pre-encounter orbit was somewhat warmer than LD2's, future thermal modeling will be needed to understand if this can explain their differences or if a more significant difference further into the past is required. This is more evidence that LD2 is a pristine and ice-rich object, and thus it may display very strong activity when it becomes a JFC. We use the differences between V6 and LD2 to discuss the interpretation of cometary activity at large heliocentric distances as well as the small end of the cratering record of the Galilean satellites. Continuing observations of both objects are highly encouraged.

Research on the thermal response characteristics of lightweight insulation structure with various shaped lattice units

The study of heat transfer characteristics of various lattice structures is necessary for the lightweight design of lattice structures, which are basic units for integrated insulation-bearing structures in the hypersonic aircraft. In this work, the heat transfer characteristics of six representative volume elements based on single-cell are investigated by numerical and experimental methods. Two lightweight insulation structures are designed using the Gibson-Ashby and tetrakaidecahedron simple-cells, which exhibit superior insulation performance. The thermal response characteristics of two structures are comprehensively investigated. The end face area of the lattice unit significantly influences the insulation performance, with a small end face area leads to a good insulation performances. Compared to the tetrakaidecahedron configuration, the Gibson-Ashby configuration demonstrates a superior insulation performance. The inner wall temperature of the structure containing the Gibson-Ashby lattice unit is consistently lower than that of the structure containing the tetrakaidecahedron lattice unit. In the ground experiments, the maximum relative temperature difference between the inner wall surfaces of the tetrakaidecahedron lattice structure and the Gibson-Ashby lattice structure is 7.6 %, while in the flight experiments, it reaches 18 %. Through heat flux inversion, flight conditions were simulated, and the results show that the temperature on the inner wall surface, which is protected by the lightweight insulation structure, remained below 320 K while the outer wall temperature reaches a high value of 423.6 K. These conclusions provide important references for the lightweight design of aircraft insulation structures.

A Study on Agri-preneurial Behaviour of Kalanamak Rice Growers in Siddharth Nagar and Sant Kabir Nagar District of Uttar Pradesh, India

Kalanamak rice, hailed for its nutritional potency and health benefits, presents a promising avenue for alleviating these challenges. This study, titled “A Study on Agri- preneurial Behaviour of Kalanamak Rice Growers in Siddharth Nagar and Sant Kabir Nagar District of Uttar Pradesh, India,” delves into this potential within the precincts of Siddharth Nagar and Sant Kabir Nagar district. The investigation hones in on two blocks – Birdpur in Siddharth Nagar, and Santha in Sant Kabir Nagar. Methodologically rigorous, the study selected six villages from each block and engaged with a total of 120 Kalanamak growers. Data collection unfurled through personalized interviews, facilitated by a meticulously crafted questionnaire. To unravel patterns and nuances, statistical tools such as frequency, percentage, mean, and standard deviation orchestrated the classification of data. The coefficient of correlation `r` was invoked to fathom the interplay between Kalanamak growers` attributes, their knowledge, and their adoption of Kalanamak rice. Analysis of the respondent demographics spotlighted several noteworthy trends. A preponderance (70.83%) emerged from the middle age group, with educational attainments peaking at the middle school (34.17%). In terms of occupation, 45% were engaged in agriculture, The agrarian landscape was marked by a significant representation from the Other Backward Classes (OBC) category (49.17%), Landholding skewed towards the smaller end (49.17%), Family dynamics, as reflected in size and structure, were characterized by medium level (64.17% and 90.83%, respectively).

High‐precision body mass predictors for small mammals: a case study in the Mesozoic

AbstractBody mass is a pivotal quantity in palaeobiology but must be inferred from an imperfect fossil record. We analyse the performance of regression models derived from various dentoskeletal predictors in mammals to inform fossils from the early, Mesozoic history of this radiation. Our focus is on the critical small end of the size spectrum; critical because the earliest mammals were small, because small size persisted onto the stems of the major extant radiations, and because small mammals compose a large proportion of crown diversity. The sampling strategy is diverse in terms of both phylogeny and skeletal predictors: the former allows a general application, while the latter enables comparison of various models. Linear regressions based on extant small mammals indicate a universal correlation of body mass with observed measurements, but with clear differences in precision. Postcranial predictors outperform jaw and dental metrics, with certain femoral joint dimensions providing surprisingly precise predictions. Our results indicate complex patterns of size evolution within the small‐bodied category, including the possibility that multiple Mesozoic species approached the theoretical lower limit of mammalian body size. The ability to study such dynamics only becomes possible when predicting body mass within a strict, highly focused phylogenetic context. The heuristic value of the models we provide here is not limited to the Mesozoic but is applicable to small‐bodied mammals of any geologic age.

Analysis of mechanical strengths of extreme line casing joint considering geometric, material, and contact nonlinearities

To address the challenges associated with difficult casing running, limited annular space, and poor cementing quality in the completion of ultra-deep wells, the extreme line casing offers an effective solution over conventional casings. However, due to its smaller size, the joint strength of extreme line casing is reduced, which may cause failure when running in the hole. To address this issue, this study focuses on the CST-ZT Φ139.7 mm × 7.72 mm extreme line casing and employs the elastic-plastic mechanics to establish a comprehensive analysis of the casing joint, taking into account the influence of geometric and material nonlinearities. A finite element model is developed to analyze the forces and deformations of the extreme line casing joint under axial tension and external collapse load. The model investigates the stress distribution of each thread tooth subjected to various tensile forces and external pressures. Additionally, the tensile strength and crushing strength of the extreme line casing joint are determined through both analytical and experimental approaches. The findings reveal that, under axial tensile load, the bearing surface of each thread tooth experiences uneven stress, with relatively high equivalent stress at the root of each thread tooth. The end thread teeth are valuable spots for failure. It is observed that the critical fracture axial load of thread decreases linearly with the increase of thread tooth sequence. Under external pressure, the circumferential stress is highest at the small end of the external thread, leading to yield deformation. The tensile strength of the joint obtained from the finite element model exhibits a relative error of less than 7% compared to the analytical and experimental values, proving the reliability of the finite element model. The tensile strength of the joint is 3091.9 kN. Moreover, in terms of anti-collapse capability, the joints demonstrate higher resistance to collapse compared to the casing body, which is consistent with the test results where the pipe body experiences collapse and failure while the joints remain intact during the experiment. The failure load of the casing body under external collapse pressure is 87.4 MPa. The present study provides a basic understanding of the mechanical strengths of extreme line casing joint.

Study on Oil Supply Characteristics of Connecting Rod Small End Bearing With Splash Lubrication by Smooth Particle Hydrodynamics Method

Abstract The lubricating oil distribution significantly impacts the lubrication and cooling of the connecting rod small end bearing during the splash lubrication. This study investigates the oil supply for the small end bearing with splash lubrication utilizing the smoothed-particle hydrodynamics. The oil distribution and inlet volume are analyzed under various engine speeds. The results reveal that the oil moves close to the piston surface and hardly enters the oil bores, resulting in oil wastage. The oil entering the bores might be thrown out due to the inertia, causing the oil inlet volume to fluctuate. With increasing engine speeds, the total oil inlet volume under the quasi-steady-state gradually diminishes, exacerbating the lubrication conditions.

High-Speed and High-Precision Online Measurement Technology for Engine Connecting Rod Weight and Barycenter

With the rapid advancement of manufacturing science and technology, the associated measurement technology has also been transformed. Traditional manual and single-instrument detection modes are unable to meet the requirements of fast beat, high precision, and online measurement in intelligent manufacturing. As connecting rods are typical and key components for automobile engines, their precision performance highly impacts the ultimate quality of engine assemblies. The online measurement of connecting rods was studied in this paper. According to the structural characteristics and parameter requirements of the connecting rods, an online multi-station measurement platform was designed and developed to measure, mark, and classify the measurements of the connecting rods in an automatic assembly line. Among these measurements, two significant parameters, the weight and the barycenter, were focused on in our work. A multi-point balance method was developed and applied to obtain the weights of the big and small ends as well as the position of the barycenter. An approach for weight sensor calibration and measurement data processing was also proposed. Finally, automatic and online measurement platforms were built for experimental verification. The results show that the measurement beats of the weight and the barycenter can reach 3 s/piece. The measured data were compared with a high-precision balance, and the average error of the connecting rod’s weight was 0.27%. The on-site application verification further proved the effectiveness and efficiency of our proposed measurement methods and machine, which enables fast and high-precision online measurement of connecting rods.

Exploring the effectiveness of emotionally focused therapy for depressive symptoms and relationship distress among couples in Taiwan: A single-arm pragmatic trial.

This is the first study to explore the effectiveness of emotionally focused couple therapy (EFT) for depressive symptoms and relationship distress among couples in Taiwan. This one-arm pragmatic trial assessed the clinical outcomes of 17 couples using multilevel modeling to investigate changes in depressive symptoms and relationship distress throughout treatment. Over half of the participants were moderately depressed and moderately distressed at baseline. Multilevel models revealed decreased depressive symptoms over time, with a small increase towardthe end of treatment. However, no significant changes were observed in relationship distress over time. The study was limited by the low "dose" of EFT (M = 7 sessions) received by participants and the small sample size (n = 17). A comprehensive discussion of the findings from a cultural perspective was provided. Future research is needed to further examine the effectiveness of EFT for couples in Taiwan and Asia.

Monitoring method of cutting forces and vibrations by using frequency separation of acceleration sensor signals during milling process with small ball end mills

Recently, there has been a further demand for precise monitoring of milling process with a machine tool by a simple and cost-effective method. One of the ways for monitoring is to install acceleration sensors to the tool spindle and estimate cutting forces from the model of the tool spindle structure. This method generally allows stable monitoring of cutting forces for tools with large diameters. However, in case of using tools with small diameters, it is difficult to estimate the cutting force due to higher frequency vibrations generated near the tool center point. Therefore, to solve the problem, we propose a new monitoring method by signal analysis of acceleration sensors in this research. The problem is that the acceleration sensor signals contain two types of signals, such as ‘acceleration change due to mechanical displacement of a tool spindle generated by cutting load’ and ‘high frequency self-excited and forced vibration’. In our method, we separate these two signals by using an approximation of sequential quadratic regression. From the former, cutting forces are estimated from equation of motions which are obtained in advance from frequency responses of the tool spindle, and from the latter, intensities of vibrations due to milling are estimated. This method was tested several milling patterns such as large cutting loads, fluctuations of cutting loads, and cutting during abnormal vibrations. As a result, we have achieved in-process monitoring of milling process not only in the X and Y directions, but also in the Z direction with a small radius ball end mill.

A new method to establish coupled multi-physics model of lubricated pin-hole oscillating pair

Under severe working conditions, about 10 % of the total engine friction loss originates from the piston pin-hole oscillating pair, significantly impacting the engine's reliability. Nevertheless, a systematic analysis encompassing the multi-physics environment (including lubrication, dynamics, and heat transfer) and their coupled behaviors is still lacking. A new coupled modeling method is proposed to achieve this, which can account for thermal deformation and frictional heat generation. All key components in this study are represented as three-dimensional flexible bodies, enabling a thorough characterization of the intricate secondary motions influencing lubrication. The method is applied to a lubricated oscillating pair test system, and a 1:1 simulation model is established. Experimental results also affirm its high accuracy. The model calculation results demonstrate that thermal deformation constrains pin secondary motions and increases axial load inhomogeneity. After factoring in fluid and asperity friction heat, the average friction coefficients at the small end hole (SEH) and pin base hole (PBH) increase by 1.8 % and 11.3 %, respectively. Furthermore, a parametric analysis is conducted, and the instantaneous friction coefficient curves under different loads/temperatures/frequencies are given. These findings can offer valuable insights into the tribological design of oscillating pairs.