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Summary The study is to determine the effects of milk powder on bone density and metabolism in healthy adolescents. Vitamin D and calcium supplements increased IGF-1 but did not affect bone mineralization or turnover. Higher vitamin D in combination with sufficient calcium supplementation in such populations requires attention. Introduction Both calcium and vitamin D play an important role in bone mineralization in adolescents. Methods In this one and a half-year randomized controlled trial, 232 participants (aged 12–15 years) were randomly assigned to three intervention groups receiving milk powder fortified with vitamin D 400 IU plus calcium 300, or 600, or 900 mg [Ca3D (n = 54), Ca6D (n = 56), and Ca9D (n = 49)], or one control group maintaining habitual diet [control (n = 73)]. Bone turnover markers, serum intact PTH, 25(OH)D, and IGF-1 levels were measured at baseline and one and a half years, and bone mineral contents and bone areal mineral density were measured by Dual-energy X-ray absorptiometry (DXA) at baseline, one year, and one and a half years. Results Baseline average serum 25(OH)D level and calcium intake were 29.4 nmol/L and 363.5 mg/day, respectively. There was a significant increase in bone turnover, total body, hip, lumbar spine bone mineral density (BMD), and total body BMC as well as slight fluctuations in 25(OH)D levels over one and a half years without between-group differences. Significantly decreased serum PTH level was only observed in the Ca6D group (31%, p

Quadrotor helicopter is light and very agile aerial robots which attracted much attention of scientists. A practical implementation of a quadrotor helicopter based on STM32 is described in this article, applying MPU6050 and other inertial sensors. The hardware structures and software flow chart of flight control are both presented. The discussions with the key problems during the process of implementation are also made.

We compare 14 glacial isostatic adjustment (GIA) models from different authors to assess how well the GIA effect could be removed from space geodetic data, such as those of the Gravity Recovery and Climate Experiment (GRACE) satellites, to study climate related and other mass changes within the Earth system. Direct comparisons of model outputs confirm unacceptably large discrepancies among models. Here we use two approximate relations within any GIA model without rotational feedback discovered by Wahr et al. (1995) , i.e., an uplift–geoid relation and an uplift–gravity relation, to test the models for internal consistency. We find that all models without rotational feedback fit the relations reasonably well with only one exception, which still appears to fit the relations, but not as well. However, some models with rotational feedback fit the relations reasonably well, while some do not. As a result, the discrepancies arising from differences in formulations or computational methods, especially rotational feedback formulations, appear to dominate over those arising from differences in ice history and Earth rheology. We conclude that the accuracy and consistency of GIA models, especially agreement of results obtained using different formulations and computational methods, need to be substantially improved to full exploit contemporary space geodetic data, such as GRACE data, to enhance the constraints on ice-sheet mass balance and the mass component of global sea-level change.

Effects of enzymatic hydrolysates of whey protein concentrates (WPC) on iron absorption were studied using in vitro digestion combined with Caco-2 cell models for improved iron absorption. Neutrase- and papain-treated WPC could improve iron absorption; especially hydrolysates by Neutrase could significantly increase iron absorption to 12.8% compared to 3.8% in the control. Hydrolysates by alcalase had negative effects to the lowest at 0.57%. Two new bands at molecular weights (MW) around and below 10 kDa occurred at tricine-SDS-PAGE of hydrolysates by Neutrase, and one new band at MW below 10 kDa occurred in hydrolysates by papain. No new band was observed in hydrolysates by alcalase. Concentration of free amino acids indicated that, except for tyrosine and phenylalanine, amino acids in papain-treated hydrolysates were higher than that of alcalase, and no cysteine and proline were found in hydrolysates by alcalase. The results suggested that hydrolysate by Neutrase-treated WPC is a promising facilitator for iron absorption. Peptides of MW around and lower than 10 kDa and aspartic acid, serine, glutamic acid, glycin, cysteine, histidine, and proline may be contributors to enhancement.

A cast nickel based superalloy M963 was coated by high-velocity oxy-fuel (HVOF) spraying process. The effect of HVOF MCrAlY coating on thermo-mechanical fatigue (TMF) and isothermal fatigue (IF) in M963 was studied to understand fatigue life and failure mechanisms in coated and uncoated M963 alloy. Two types of TMF tests, i.e. in-phase (IP) and out-of-phase (OP), were performed in temperature range of 450~900°C, and IF tests were conducted at 900°C. It was found that the coating had a detrimental effect on fatigue life under OP TMF, while a beneficial effect of the coating existed under IP TMF and IF. Crack initiation time in the coated specimen was shorter than that in the uncoated specimen and the former’s crack density was higher than the latter’s one under OP TMF. The relationship of deformation and fracture response with fatigue life was discussed based on microscopic analysis.

The effect of cold rolling on two-way shape memory was investigated by x-ray diffraction technique and TEM in a Cu-18Al-10.5Mn (at.%) alloy. Cold rolling leads to a preferred orientation distribution on the stress-induced martensite with 6M-structure, which leads to the dependence of two-way shape memory on the specimen directions. The relationship of stress state and anisotropy of 6M-structured martensite lattice inside cold rolling deforming region is elucidated through analyzing the deformation process-related variant selection according to original grain orientation.

The inverted tube can be used as an energy absorber in transport vehicles like aircraft and automobiles. The aim of this paper is to contribute to an extension of the actual knowledge of the deformation process and mechanical parameters by means of finite element simulation. Experiments were performed on 3A21 alumimium alloy tubes and 1Cr18Ni9Ti stainless steel tubes, mainly utilized for supporting and validating the results of finite element simulation. An experimental setup to investigate the energy absorbing capacity of inverted tube was designed. The investigation indicates: (1) the value of die radius or half-tapered-angle makes an important influence on the stability of external inversion and quality of the inverted tube; (2) the deforming load of inverted tubes under quasi-static load is very stable with a good energy absorbing capacity; (3) the finite element simulation results agree with the experimental ones.

Tinnitus could be associated with neuronal hyperactivity in the auditory center. As a neuronal activity marker, immediate-early gene (IEG) expression is considered part of a general neuronal response to natural stimuli. Some IEGs, especially the activity-dependent cytoskeletal protein (Arc) and the early growth response gene-1 (Egr-1), appear to be highly correlated with sensory-evoked neuronal activity. We hypothesize, therefore, an increase of Arc and Egr-1 will be observed in a tinnitus model. In our study, we used the gap prepulse inhibition of acoustic startle (GPIAS) paradigm to confirm that salicylate induces tinnitus-like behavior in rats. However, expression of the Arc gene and Egr-1 gene were decreased in the inferior colliculus (IC) and auditory cortex (AC), in contradiction of our hypothesis. Expression of N-methyl d-aspartate receptor subunit 2B (NR2B) was increased and all of these changes returned to normal 14 days after treatment with salicylate ceased. These data revealed long-time administration of salicylate induced tinnitus markedly but reversibly and caused neural plasticity changes in the IC and the AC. Decreased expression of Arc and Egr-1 might be involved with instability of synaptic plasticity in tinnitus.

This paper reports a detailed electron microscope study of slip occurring at the fatigue crack tips for an intermetallic fully lamellar TiAl alloy. The formation mechanism of the slip bands, their nature and constitution and the relationship between the slip bands and microcracking have been suggested.

This paper describes a systematic modelling of a general cracked tubular Y-joint commonly found in offshore structures. The Y-joint under consideration may contain either a through-thickness or surface crack which can be of any length and located at any position along the brace–chord intersection. This is particularly significant, as it has always been found in practice that the initiation site of a surface crack does not always start from the saddle or crown position when tubular joints are subjected to a complex loading condition. The geometrical model developed in the work described in this paper includes the weld detail which is compatible with the American Welding Society (AWS) standard [1] . Based on this geometry, well-graded finite element (FE) meshes were generated for a T-joint, which is a specific type of Y-Joint, to obtain the stress intensity factors (SIFs) for a surface semi-elliptical crack along the crack tip using quarter-point elements. The numerical analysis indicated that the FE models generated are appropriate to the geometry of the joints since converging values of SIF were obtained as the meshes used were refined. The accuracy of the Mode I, Mode II and Mode III SIFs demonstrates that the proposed model is reliable.

Large numbers of fine parallel steps are generated on translamellar fracture surfaces during slow crack growth (d a /d N ≤5.0×10 −6 mm/cycle) under cyclic loading. These are seen only rarely during fast crack growth (d a /d N ≥1.0×10 −4 mm/cycle) and are not seen during catastrophic fracture. These steps occur due to intense plastic deformation as a result of cleavage on {111} planes along twin boundaries and dislocation bands. Such action may promote an inherent resistance to crack growth owing to higher energy dissipation. TEM examinations show that the intense deformation structure consists of both microtwins and dislocation bands if the lamellae are orientated to allow easy glide. Conversely, microtwin activity dominates when easy dislocation glide is prevented. Crack initiation and growth resistance are sensitive to such microscopic features within the deformation zone. Lamellar volume fraction, the proportion and distribution of γ grains inside lamellae and lamellar interfacial strength may all influence the local plastic deformation through their interaction with underlying slip and twinning processes.

From fatigue fracture surface examination on fully lamellar microstructure of {gamma}-TiAl alloys, intralamellar crack propagation has been reported recently. Compared with the investigation of translamellar and interlamellar fractures, the characteristic features of intralamellar fatigue fracture have not been investigated in detail. Intralamellar crack propagation on the fatigue fracture surface is found same as interlamellar propagation, parallel to lamellar interfaces but is characterized by complicated geometric patterns of microcracking traces on consecutive lamellar plates, while translamellar propagation occurs transverse to the lamellar boundaries. These geometric patterns may relate to deformation traces occurring in areas local to the growing crack tip. An investigation into intralamellar fracture to explain its crystallographic features is merited. In this paper attention will be concentrated on fully lamellar microstructure subjected to cyclic loading since this condition demonstrates a considerable amount of intralamellar fatigue fracture and can achieve improved crack growth resistance relative to near lamellar and duplex microstructures.

The compartmental method is effective for the simplified dynamic modelling of distillation processes, but there are usually an unexpected inverse response and large dynamic error in the initial stage. Furthermore, the computation is complicated in that each particular column has to be dealt with in an individual way. In order to overcome these drawbacks, this paper presents a improved compartmental method, based on the introduction of two types of ‘standard’ separation blocks. Separation functions of these blocks are derived, so that computation for columns with diversified structure can be carried out in a systematic manner. By varying block parameters and variables, any real column met in practice can be readily modelled by a suitable number of standard separation blocks. The results of a simulation sample made on a 100 tray, 16 component xylene column show that the above mentioned drawbacks are removed. The proposed modelling method can be used for fast simulation and control of columns in industrial practice.

Modified network architecture for sorting data of any size is presented in this paper. The proposed VLSI archi- tecture is directly modified from the Batcher's odd-even merge-sort network. The major advantage of the proposed architecture is its modular approach, simple and regular interconnection and easy implementation by VLSI technol- ogy.

Average spectrum of electrophysiological cochlear activity (ASECA) recorded from the cochlea or the eighth nerve is related to firing of auditory neurons and has been used recently in search of an objective measure of tinnitus both in animal models and in humans. Little is known about neuro-sensory processes underlying the spectral features of ASECA. The present study used awake and/or anesthetized animals and investigated effects of various sounds presented contralaterally and ipsilaterally. Contralateral stimulation with noise bands at frequencies above about 8 kHz and below acoustic interaural cross-talk decreased the amplitude of the 1 kHz peak of ASECA. When presented ipsilaterally noises produced either an increase or a decrease of this spectral peak when the acoustic bandwidth was respectively above or below 1.5 kHz. Pure tones when presented contralaterally had no detectable effect. When presented ipsilaterally pure tones with frequencies higher than about 4 kHz decreased the 1 kHz peak of ASECA. The detailed time course of sound-induced variations of the 1 kHz peak was measured by time averaging. The resulting response patterns resemble PST histograms of the auditory nerve. Sedation and anesthesia deepened the 500 Hz trough of ASECA and shifted it towards 400 Hz. Sedation induced a diminution and anesthesia an almost complete suppression of the decrease of the 1 kHz peak induced by contralateral noise. Overall these data indicate that ASECA would reflect synchronized firings and they provide evidence for an influence of olivo-cochlear feedback sensitive to the state of awakeness.