Neck Thickness Research Articles

Parametric Study of Hybrid Metal-Composites Clinching Joints

In different innovative markets, such as electro mobility and flexible electronics, among others, the mechanical joining processes based on sheet metal forming technologies are gaining a significant relevance due to their low cost and ease of automation as compared to traditional joining techniques of riveting, bolting, fastening, welding, etc. In lightweight hybrid constructions, where a high production rate is required, clinching technology demonstrates a sustainable method to join hybrid metal-composite parts. However, the basic mechanisms of this hybrid joining process are not well studied at present and an accepted design theory in this area has not yet been established. The current contribution presents a parametric study of the hybrid clinching joining process. The Taguchi’s design of experiments method is used to investigate the effects of tools’ geometry on hybrid clinching joints’ quality characteristics, i.e. neck thickness, undercut and final bottom thickness. For this purpose, a 2D axisymmetric modelling approach was adopted for its simplicity. The study results are analyzed using the mean response and signal-to-noise ratio approaches. Accordingly, the relevant geometrical parameters of the tools with the highest influence on the accurate shaping of hybrid clinching joints are determined numerically.

Laser shock micro clinching of Al/Cu

The influences of ablative layer, soft punch, die depth, and laser energy on novel micro clinching of Al/Cu were investigated. Ablative layer thickness notably influenced metal flow including neck and interlock; the relationship between reasonable ablative layer thickness and certain laser energy range was summarized. Soft punch with 100 μm was more suitable than with other thickness for the process. In the joinable laser energy range, with increase of laser energy, interlock thickness gradually increased, whereas the neck and bottom thicknesses gradually decreased. The process window of Al/Cu combination was acquired, and a certain thickness difference which was at least 40 μm inevitably existed between the upper and lower metal foils. For every joinable combination, matching function of optimum die depth are derived based on Al and Cu foil thickness when the thickness of each metal foil was less than 200 μm. The single lap shearing test showed that the tensile strength and failure model of the joint both depended on neck and interlock thicknesses; only the joint that simultaneously formed a large interlock and large neck can attain a high joining strength.

Obstructive sleep apnoea, obesity hypoventilation, trisomy 21 and intellectual disability in a 19 year old female – 2016 – Royal Melbourne Hospital

Introduction: Obesity Hypoventilation Syndrome (OHS) is estimated to occur between 10% and 20% of patients with obstructive sleep apnoea (OSA) (Mokhlesi et al., 2008; La Aban and Chailleux, 2005). The most common symptoms and signs are due to the co-existing OSA (Mokhlesi, 2007), and include excessive daytime sleepiness, loud snoring, choking during sleep, resuscitative snorting fatigue, hypersomnolence, impaired concentration and memory, a small oropharynx, and a thick neck (Nowbar et al., 2004). Non-invasive ventilation is an effective form of treatment in patients with obesity hypoventilation syndrome (OHS), and have obstructive sleep apnoea (OSA) (Salord et al., 2013).

Effect of HF/HNO3-treatment on the porous structure and cell penetrability of titanium (Ti) scaffold

Porous titanium (Ti) implants have been used in orthopedic and dental applications because of their superior mechanical properties. Sufficient pore interconnectivity is required for effective bone regeneration and growth inside the Ti scaffold pore structure. We proposed post-treatment with HF/HNO3 to efficiently modify the internal pore structure of a Ti scaffold and achieve controllable mechanical properties with a pore neck structure. The porosity, pore size, wall thickness, and pore neck size were easily controlled by varying the acid treatment time, which produced a Ti scaffold with mechanical properties that were suitable for bone tissue engineering. As the mixed acid treatment time increased, internal isolated pores were gradually interconnected with adjacent pores. After 10min of treatment, nearly all the pores were interconnected. The post-treatment with HF/HNO3 also affected the surface properties. Surface carbon contaminants were significantly reduced after treatment with no hydride formation. Micron-scale surface roughness was uniformly generated across the whole surface. The actual cell penetrability of the Ti scaffold was evaluated using a perfusion-based in vitro cell test. Over 90% of the surface pores depict cell penetrability with a sufficient number of cells attached to the wall surface of the pore after performing acid treatment for 12min.

Experimental investigation and comparison of Newtonian and non-Newtonian shear-thinning drop formation

The presence of small amount of polymer in Newtonian liquids affects the fluid behavior significantly and creates superficial differences between Newtonian and non-Newtonian drop formation. In the present study, Newtonian and non-Newtonian shear-thinning drop formation in air is examined experimentally and the geometrical parameters, such as drop elongation length, minimum neck diameter and current contact angle are studied for water, glycerin solutions (79, 89 and 94% w/w) and Carboxymethyl cellulose (CMC) solutions (0.5 to 1.5% w/w) drops. The results indicate that at initial stages of the drop growth, Newtonian and non-Newtonian liquids behave similarly. However, at the start of the necking process in which the deformation rate increases, clear differences can be seen between Newtonian and shear-thinning fluids. The most important effects of an increase in the glycerin and CMC concentration, which enlarges the viscosity, are an increase in the time span of the necking process, a decrease in the elongation rate, an increase in the length of the liquid filament and an increase in the probability of the satellite drop formation. On the other hand, due to the shear-thinning properties of CMC solutions, their viscosity decreases in the necking region and as a result, the length of the Newtonian drop at the moment of separation is longer than that of the shear-thinning drop with equal viscosity. The variation of minimum neck thickness with the time remaining until the detachment for the investigated liquids is presented by hmin∝(td-t)α, in which α is 2/3 for water, 1 for viscous Newtonian fluids, and for non-Newtonian shear-thinning fluids it is equal to the index of fluid in the power-law relation.

Effect of biofertilizers with graded levels of nitrogen and phosphorus on growth and yield of garlic (Allium sativum L.)

The experiment was carried out at the Horticultural Research Station, Mondouri, BCKV, West Bengal during 2013–14 and 2014–15. In both the years, cloves of garlic cv. Katki were planted during 1st week of November in 2.0 x 1.5 m plots, at 20 x15 cm spacing accommodating 100 plants per plot. The experiment was laid in RBD with three replications. Four biofertilizers, namely, Azospirillum brasilense, Azotobacter chrococcum, vesicular arbuscular mycorrhizae (Glomus fasciculatum) and phosphate solubilizing bacteria (Bacillus polymixa) were applied @ 6 g per plot each with 250 g well rotten FYM. Different combinations of nitrogenous and phosphatic biofertilizers along with three levels i. e. 100, 75 and 50% of recommended dose of nitrogen and phosphate were included in the experiment. There were altogether 13 treatments including control. NPK dose was 150: 125: 150 kg/ha. Maximum plant height (74.32 cm), leaf number (11.86), bulb weight (26.34 g), plot yield (2.76 kg/3 m2) and projected yield (6.92 t/ha) were recorded with NP (100%)+Azospirillum+VAM. The next best treatment in respect of yield was NP (100%)+Azotobacter+VAM (6.71 t/ha) followed by NP (75%)+Azospirillum+VAM (6.37 t/ha). The maximum number of cloves (28.25), neck thickness (1.06 cm) and length of both long clove (2.93 cm) and medium clove (1.96 cm) were noticed with NP (100%)+Azotobacter+VAM. From yield maximization point of view, the most effective treatment was NP (100%)+Azospirillum+VAM followed by NP (100%)+Azotobacter+VAM under alluvial plains of West Bengal for garlic production.

Growth and yield of garlic as influenced by foliar application of urea and micronutrients

A field experiment was conducted during Rabi season of 2014–15 to study the effect of foliar spray of different levels of urea (0.5, 1.0, 1.5 and 2.0%) in combination with micronutrients such as ZnSO4, MnSO4, FeSO4 each at 0.5% and CuSO4 at 0.2%. Urea and micronutrients along with sticker were applied at 30, 45 and 60 days after planting. Total seventeen treatment combinations including control were laid out in randomized block design with three replications. The cloves of garlic cv. HG-17 were planted at a spacing of 15×10 cm in a plot size of 3.0×3.0 m. Foliar feeding of 0.5% zinc sulphate in combination with 1.5% urea three times at 15 days interval gave superior results with respect to measured parameters. The maximum plant height (36.38 and 53.80 cm) at 30 and 60 days after planting, leaf length (28.17 cm), neck thickness (9.47 mm), number of cloves per bulb (37.17), clove length (25.05 mm), fresh and dry weight of individual clove (0.95 and 0.46 g), total plant biomass (44.40 g) and total bulb yield (155.51 q/ha) was registered with foliar application of 0.5% zinc sulphate in combination with 1.5% urea, followed by 2.0% urea application in combination with 0.5% zinc sulphate.

Herbicides effect on growth, yield and quality of onion

A field experiment was conducted at Birsa Agricultural University, Kanke, Ranchi, during the year 2016–17 to study the effect of herbicides on growth, yield and quality of onion. The treatments comprised of application of oxyfluorfen (0.25 kg/ha) one week before transplanting, oxyfluorfen (0.25 kg/ha) immediately after transplanting, pendimethalin (1.00 kg/ha) one week before transplanting, pendimethalin (1.00 kg/ha) immediately after transplanting, pretilachlor (0.75 kg/ha) one week before transplanting, pretilachlor (0.75 kg/ha) immediately after transplanting, quizolofop-ethyl (1.00 kg/ha) 20 days after transplanting (DAT), hand weeding (HW) and weedy check. Results revealed that highest plant height (66.67 cm), number of leaves (5.98) and neck thickness (4.76 cm) were recorded in hand weeding at all the growth stages, which was at par with pendimethalin immediately after transplanting and pendimethalin one week before transplanting.The increase due to HW was in the tune of 78.88, 55.73 and 59.20% respectively than weedy check whereas, pendimethalin immediately after transplanting of onion recorded 63.94, 52.56 and 51.84% increase over weedy check. Hand weeding recorded 122% more yield (23.71 t/ha) than weedy check (10.68 t/ha). Juice content and TSS was the highest in hand weeding which was at par with pendimethalin immediately after transplanting, application of pendimethalin one week before transplanting and oxyfluorfen immediately after transplanting.

Beef Cattle Fattening Practices and Marketing Systems in Gondar Town, Amhara, Ethiopia

The objective of the study was to describe the cattle fattening practices and the existing marketing systems. For this study, four farmer associations were selected on purpose. From each PA, 20 respondents (a total of 80 HH) were randomly selected from owners who practice fattening cattle and the data was collected using a semi-structured questionnaire and observation. The collected data were analyzed by using SPSS version 20 software.In the study area, the food resources used for their fattening cattle were 67.5%, 17.5% and 15.0% of wheat and corn bran, bean and rice bran and the mixture of bean + peacoat + hay as feed for their fattening cattle without scientific formulation, respectively. The sources of water used by respondents were 72.5% and 27.5%, respectively, for river and strip water. The finding revealed that majority of fatteners was select cattle based on phenotypic characteristics of the cattle by body frame (58.8%), glossy coat color (31.2%), wide/deep body condition (7.5%) and thick neck (2.5%). The survey result indicated 65.0% and 35.0% of respondents used trekking and vehicle (trucking) transporting practices, respectively. Even though, weight measurements had not practiced in the area, 87.5% respondents price set factor were depending on live weight of animals. The current study showed that the main constraints of beef cattle fattening practices in Gondar town were feed cost increase (30.0%), lack of credit (12.5%) and absence of market information (16.2%).In general, the fattening practices of beef cattle in the study area were constrained by various challenges and not supported by improved fattening technology. In order to increase the profitability of feeders, the provision to farmers of adequate training and extension services on improved livestock fattening technologies, key management practices and market information should be mandatory.

Investigation of Flat Clinching Process Combined with Material Forming Technology for Aluminum Alloy.

In recent years, the use of aluminum alloy has tended to increase for building lightweight automobiles to reduce their automotive weight, which is helpful to save energy and protect the environment. In order to join aluminum alloy, a flat-clinching process combined with material forming technology was investigated to join aluminum alloy sheets using an experimental and a numerical method. Al1060 was chosen as the material of the sheet, and DEFORM-2D software was used to build the numerical model. After the numerical model was validated by the experimental results, the influences of punch diameter and holder force on the materials deforming behavior of the clinched joint were analyzed using the numerical model. Then, the material flow, joining ability, and joining quality were investigated to assess the clinched joint. The results showed that an increase in punch diameter could give rise to an increase in neck thickness and interlocking length, while an increase in blank holder force induced a decrease in interlocking length and an increase in neck thickness. The joining quality could be increased by increasing the forming force. It can be concluded that a clinched joint has better joining quality for joining light-weight sheets onto automotive structures.

Effect of potash and sulphur on yield and quality parameters under different planting methods in onion

A field experiment was carried out to examine the effect of potash and sulphur on yield and quality parameters under different planting methods in onion (Allium cepa L.) during Rabi 2014 and 2015. The experiment consists of 8 treatment combinations viz. 2 planting methods (bed and flat), 4 treatments of fertilizer viz. S1-N100 P50 K0 S0 (control), S2 - N100 P50 K50 S0, S3 - N100 P50 K0S40, S4 - N100 P50 K50 S40. The experiment was laid in factorial randomized block design and replicated thrice. Uniform dose of farm Yard manure (50 t ha-1) was applied to all the treatments. Data on plant height (cm), leaves /plant (No.), neck thickness (mm), fresh bulb weight (g), fresh bulb yield (q ha-1), total soluble solids (T.S.S), sprouting (%),rotting (%) and physiological weight loss (%) at 30 and 90 days after of harvest were recorded . It has been observed that planting methods and fertilizer treatments showed significant difference at 5% level of significance for plant height (cm), neck thickness (mm), fresh bulb weight (g), fresh bulb yield (q ha-1),total soluble solids (T.S.S), sprouting(%), rotting(%) and physiological weight loss (%) at 30 days after harvest. However their interaction was significant for Neck thickness (mm), fresh bulb yield (q ha-1) and rotting (%).It was found that application of potash and sulphur with recommended dose of Nitrogen and phosphorus gave better results in relation to yield as well as quality characters. The results revealed that application of potash and sulphur with recommended dose of nitrogen and phosphorus (S4 - N100 P50 K50 S40 ) gave better results in relation to yield (339.6 q ha-1) as well as quality characters like sprouting (2.38 %) and rooting (12.18 %) and physiological weight loss at 30 and 90 days of harvest(10.22 and 20.50 % respectively).

Different Clinical Characteristics Between Distal Cholangiocarcinoma and Pancreatic Head Carcinoma With Biliary Obstruction

The aim of this study was to compare the perioperative clinical characteristics between patients with distal cholangiocarcinoma (DCC) and pancreatic head carcinoma (PHC) with biliary obstruction. This study included patients who underwent pancreatoduodenectomy and were diagnosed with DCC (n = 85) or PHC (n = 90) by final pathological examination. Perioperative clinical characteristics were compared for patients with DCC versus PHC with biliary obstruction. Median coronal thickness of the pancreatic neck was significantly greater, whereas the main pancreatic duct diameter was significantly smaller in patients with DCC than patients with PHC. Most patients with DCC (95%) had a soft pancreas, whereas only 29% of patients with PHC had. The incidence rates of overall morbidity, infectious complications, and pancreatic fistula were significantly higher in patients with DCC than those in patients with PHC. Eleven DCC patients (12%) were preoperatively misdiagnosed with PHC. Among them, intraductal ultrasonography of the bile duct was performed in 7 patients, and the presence of PHC was suspected in 3 of these patients because intraductal ultrasonography detected a small intrapancreatic mass. This study clearly showed different perioperative characteristics between patients with DCC and PHC. It is not uncommon to misdiagnose PHC as DCC. Intraductal ultrasonography may be helpful in differentiating DCC and PHC.

Effects of the Neck Stabilization Exercises with Vibratory Stimulation on the Neck Disability Index and Thickness of Deep Neck Flexor in Neck Pain Patient

Effects of the Neck Stabilization Exercises with Vibratory Stimulation on the Neck Disability Index and Thickness of Deep Neck Flexor in Neck Pain Patient

Formation mechanisms of solid in water in oil compound droplets in a horizontal T-junction device

The formation mechanisms of S/W/O compound droplets in a horizontal T-junction device was investigated. According to the capillary number, Ca, of a continuous phase and the ratio, R, given by R = Qmain/Qside, the formation mechanisms which are the double-encapsulation, squeezing regime, dripping-like regime, and the jetting-like regime can be distinguished. In the squeezing regime, the lag of the PS shell relative to the W phase results in a different squeezing stage, in which the neck thickness decreases firstly and then increases because of the limited deformation of the W/O interface by the PS shell. After the PS shell totally intrudes into the main channel, the neck thickness decreases again. In the dripping-like regime, the gap distance decreases linearly with the entry of the PS shell into the main channel. Therefore, compared with W/O droplets in dripping regime, the dominant force that breaks off the neck remains to be the pressure drop force, and not the shearing force, because of the comparatively large diameter of the PS shell to that of the channel. A high Ca and low R contribute to the formation of the jetting-like regime, in which the inertia force and shearing force contribute to the formation of a long tip because of the large flow rates in the main and side channel. In addition, regimes in the flow pattern diagram dependent on Ca and R are obtained.

Patient-specific Factors Associated with Difficult Mask Ventilation in the Emergency Department

Summary Background Difficult mask ventilation (DMV) leading to oxygen and ventilation failure can cause complications and fatal consequences in airway management, but has rarely been studied as a primary outcome in the emergency department (ED). This study aimed to determine the incidence and predictors of DMV in the ED. Methods A specially designed form recording potential risk factors for DMV was designed and subsequently completed by a research nurse and physicians who had performed the procedure for all mask ventilation attempts over a one-year period in the ED of a large hospital in Taipei, Taiwan. Univariate associations between patient characteristics and DMV were measured, and a risk assessment scale was created according to the independent risk factors for DMV ascertained by adjusted regression models. Results One hundred ten mask ventilation attempts were recorded during the study period. DMV occurred frequently in the ED (45.9% of mask ventilation attempts). Significantly elevated rates of DMV were observed in patients aged 65 years or older those lacking teeth, with sunken cheeks, a double chin or a thick short neck. In adjusted analyses, three easily recognizable predictors, namely lack of teeth, sunken cheeks, and a double chin were found to be independent risk factors for DMV, and accordingly a risk assessment scale- LSD method was made. Conclusion DMV is a frequent challenge in EDs. An easy-to-use LSD risk scale is created for clinicians to rapidly identify and appropriately manage the risk patients of DMV.

Influence of sheet thickness on mechanical clinch–compress joining technology

A mechanical clinch–compress joining technology was investigated to join sheets with different thicknesses in the present study. A pair of flat dies was used to compress the clinched joint, and a rivet was used to increase the joining strength. Al5052 sheets with different thicknesses were used to conduct the joining experiments. Tensile strength test and shearing strength test were conducted to evaluate the quality of the compressed joint. Failure mode, feasibility of the joining method, neck thickness, tensile strength, shearing strength, and energy absorption were investigated to show the mechanical properties of the compressed joint. The main failure mode of the joints is neck fracture mode, which means that the neck thickness determines the strength in this study. The mechanical clinch–compress joining technology can increase the strength and energy absorption of the joint by increasing the neck thickness. The joint with a thick upper sheet also can get higher strength and energy absorption by producing a thicker neck thickness. The mechanical clinch–compress joining technology can be used in the visible areas where higher strength and lower protrusion are needed.

Die-less clinching process and joint strength of AA7075 aluminum joints

AA7075 aluminum alloy sheets in different temper conditions (O, W and T6) were joined by die-less clinching. The material flow behavior, neck thickness and interlock characteristics during clinching were investigated by metallographic observations of clinched, cut and mounted samples. Blank holders of different shapes and dimensions were used to control the material flow. The effects of blank holder geometric parameters as well as forming forces on the shape of the formed interlock in clinching were studied. The highest strength temper state (T6) was shown to possess poor clinch-ability as it failed to clinch under most clinching conditions. This was attributed to its poor ductility and formability at room temperature compared to the other tempers. Lastly, mechanical performance of the formed joints was characterized by conducting single shear lap as well as peel tests. Various failure modes were observed for the different clinching conditions and material temper states.

Alterations in yield, physicochemical components and mineral composition of onion following organic manure and inorganic nitrogen application

ABSTRACTOnion is the one of the most important vegetable crops grown extensively throughout the world; hence, understanding the response of the crop to the form and amount of N provided is of immense importance. In a field experiment, poultry and cattle manure (at 10 t/ha) were compared with four inorganic nitrogen (N) application levels (0, 60, 90 and 120 kg N/ha), and six combinations of manure and N applications were investigated. Plant growth and total yield (kg/ha) significantly increased, when N application increased from 0 to 120 kg/ha, with or without added poultry manure. Plant height, leaf number and neck thickness were significantly reduced at 0 kg/ha N plus cattle manure. The bulb ascorbic acid concentration significantly increased with the use of poultry manure (15.94 mg/100 g) and cattle manure (15.94 mg/100 g), compared with 120 kg/ha inorganic N (11.42 mg/100 g). No significant effects were observed on total phenolics and total soluble solids of onion bulbs following the different fertiliser treatments. Cattle manure increased P and K concentrations, whilst poultry manure significantly increased Zn and Fe concentrations in onion bulbs. Onion bulb Ca and Mg concentrations were lower when cattle manure (0.19% and 0.12%) was used than when other organic or inorganic fertilisers were used. Therefore, organic manure increases the concentrations of certain minerals in onions, compared with inorganic N application, without negatively affecting bulb size.

Spatiotemporal Optoacoustic Mapping of Tumor Hemodynamics in a Clinically Relevant Orthotopic Rabbit Model of Head and Neck Cancer

The purpose of this study was to investigate the usefulness of photoacoustic imaging (PAI) for spatiotemporal mapping of tumor hemodynamics in a rabbit model of head and neck carcinoma. Shope cottontail rabbit papilloma virus associated VX2 carcinomas were established in adult male New Zealand White rabbits (n = 9) by surgical transplantation of tumor tissue in the neck. Noninvasive PAI with co-registered ultrasound (US) was performed to longitudinally monitor tumor growth, oxygen saturation (%sO2), and hemoglobin concentration (HbT). PAI findings were validated with Doppler sonography measures of percent vascularity (PV). Differences in tumor volumes, %sO2, HbT, and PV values over time were analyzed using repeated-measures analysis of variance with multiple comparisons. Two-tailed Spearman correlation analysis was performed to determine the correlation coefficient (r) for comparisons between %sO2, HbT, and tumor volume. US revealed a significant (P < .0001) increase in tumor volume over the 3-week period from 549 ± 260 mm3 on day 7 to 5055 ± 438 mm3 at 21 days postimplantation. Consistent with this aggressive tumor growth, PAI revealed a significant (P < .05) and progressive reduction in %sO2 from day 7 (37.6 ± 7.4%) to day 21 (9.5 ± 2.1%). Corresponding Doppler images also showed a decrease in PV over time. PAI revealed considerable intratumoral spatial heterogeneity with the tumor rim showing two- to three-fold higher %sO2 values compared to the core. Noninvasive PAI based on endogenous contrast provides a label-free method for longitudinal monitoring of temporal changes and spatial heterogeneity in thick head and neck tumors.

Leidenfrost drops cooling surfaces: theory and interferometric measurement

When a liquid drop is placed on a highly superheated surface, it can be levitated by its own vapour. This remarkable phenomenon is referred to as the Leidenfrost effect. The thermally insulating vapour film results in a severe reduction of the heat transfer rate compared to experiments at lower surface temperatures, where the drop is in direct contact with the solid surface. A commonly made assumption is that this solid surface is isothermal, which is at least questionable for materials of low thermal conductivity, resulting in an overestimation of the surface temperature and heat transfer for such systems. Here we aim to obtain more quantitative insight into how surface cooling affects the Leidenfrost effect. We develop a technique based on Mach–Zehnder interferometry to investigate the surface cooling of a quartz plate by a Leidenfrost drop. The three-dimensional plate temperature field is reconstructed from interferometric data by an Abel inversion method using a basis function expansion of the underlying temperature field. By this method we are able to quantitatively measure the local cooling inside the plate, which can be as strong as 80 K. We develop a numerical model which shows good agreement with experiments and enables extending the analysis beyond the experimental parameter space. Based on the numerical and experimental results we quantify the effect of surface cooling on the Leidenfrost phenomenon. By focusing on the role of the solid surface we provide new insights into the Leidenfrost effect and demonstrate how to adjust current models to account for non-isothermal solids and use previously obtained isothermal scaling laws for the neck thickness and evaporation rate.