Accuracy improvement of built-in torque sensing for Harmonic Drives

Built-in torque sensing for Harmonic Drives is attractive since it maintains mechanical characteristics of the gear while providing detection of the transmitted torque. Torque sensing by using strain gauges has been studied, but is not widely used yet due to a relatively high signal fluctuation, which is generated by the gear operation. Characteristics of the signal fluctuation are analyzed in this paper, and a method to effectively compensate the signal fluctuation is proposed. The signal fluctuation is perfectly compensated by adjustment of the strain gauge sensitivities. A minimum number of strain gauges needed to compensate the signal fluctuation is derived. The experimental result with three strain gauges compensating the basic frequency component of the signal fluctuation is shown     

Segmentation of plant hairy roots promotes lateral root emergence and subsequent growth

The influence of root cutting on the emergence of lateral roots was investigated in the cultures of horseradish and madder hairy roots. The original hairy roots prepared for inoculation were cut at various distances from the tips and the resultant segments were cultivated in flasks. It was found that lateral roots very frequently emerged from the segments, depending on the longitudinal positions at which the segments were obtained. To attain the effective growth, cultivation of madder hairy roots with root cutting performed twice at 0 and 360 h was conducted. The emergence of lateral roots facilitated the growth of hairy roots owing to an increase in the number of growing points (GPs). The dry cell mass concentration and the number of GPs were 9.6 kg/m3 and 1.9 x 10(7)/m3 at 672 h of culture time, which were 3.6 and 4.9 times higher, respectively, than those in the control culture without the operation.     

Estimation of liquidus temperature of Sn-based alloys and its application to the design of Pb-free solder

An interesting relation between the melting temperature and the alloy composition was discovered in Sn-based alloys through the evaluation of a series of experimental data on the liquidus temperatures (LTs) for 134 types of multi-component Sn alloys. In these Sn alloys, the degree of liquidus temperature drop with alloying was not affected by the kind of individual elements but by their total atomic fraction alone. The compositional dependence on the LT could be expressed by the equation, LT(K)=499.79–1.799X, where X was the total mole percentage of alloying elements. It was demonstrated that the use of this equation would make it possible to develop Pb-free solder alloys more efficiently.     

Total sputtering yields of solids under MeV-energy Si ion bombardment

Total sputtering yields have been measured for SiO₂ and Cu targets bombarded with Si ions at an incident energy between 500 keV and 5.0 MeV using a quartz crystal microbalance technique. In order to measure total yields accurately, we have developed a beam modulation technique to avoid the effect of thermal drift. In the MeV energy range, an ion penetrates through thin SiO₂ and Cu targets and is implanted into a quartz crystal. Therefore, the thickness of these layers deposited on quartz crystals was carefully controlled to avoid damage of quartz crystal by incident ions. As a result, total sputtering yields of SiO₂ increased with incident Si ion energy, while those of the Cu target decreased. The total yields of the SiO₂ target were represented well by a power low of the electronic stopping power.     

Predictors for the massive thrombi occurring in the right coronary artery related to acute myocardial infarction

Acute myocardial infarction (AMI) related to the right coronary artery (RCA) is associated with a lower reperfusion rate and higher reocclusion rate in the acute phase than AMI related to the left coronary artery. The greater susceptibility of the RCA to development of large thrombi makes successful reperfusion more difficult to achieve. This study investigated predictive factors for massive thrombus in the RCA before the selection of the treatment to achieve better rates of reperfusion. We classified 51 patients with AMI related to RCA into the massive (linear intraluminal radiolucency > 3 cm) thrombus group (9 patients) and the non-massive thrombus group (42 patients). 1) History: Patients in the massive thrombus group had a greater incidence of hypertension than the non-massive thrombus group, with more left ventricular hypertrophy (p < 0.05). There were no significant differences in other coronary risk factors. 2) RCA morphology: The maximum RCA diameter was significantly greater in the massive thrombus group than that in the non-massive thrombus group [proximal to the right ventricular branch, 4.2 vs 3.2 mm (median); distal to the right ventricular branch, 4.2 vs 3.4 mm, p < 0.05]. 3) Conditions of onset: The elapsed time was significantly longer in the massive thrombus group (15 hours) than that in the non-massive thrombus group (2.5 hours, p < 0.05). More massive thrombus cases were observed in summer (p < 0.05), but there was no evident correlation between massive thrombus formation and the onset time of day, weather, Hct and coagulation factor at the onset, left ventricular ejection fraction or left ventricular end-diastolic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Laparoscopic cholecystectomy using the abdominal wall lift in a cardiac patient

We present a case report of a patient with impaired cardiac function after aortic valve replacement and open mitral commissurotomy who underwent a laparoscopic cholecystectomy for cholecystolithiasis. In preventing reduced cardiac output due to pneumoperitoneum, the laparoscopic operative procedure was performed using the abdominal wall lift. Cardiac function was continuously evaluated by transesophageal echocardiographic examination and remained stable during the surgery. Because of the patient's co-existing chronic atrial fibrillation and prosthetic aortic valve, perioperative anticoagulation management was carried out. The patient's post-operative course was uneventful, and he was discharged on the 7th post-operative day.     

Solid‐state linear viscoelastic properties of intercalated poly(L‐lactide)/organo‐modified montmorillonite hybrids

Hybrids of poly(L ‐lactide)/organophilic clay (PLACHs) have been prepared by a melt‐compounding process using poly(L ‐lactide) (PLLA) and different contents of surface‐treated montmorillonite modified with a dimethyl dioctadecyl ammonium salt. The dispersion structures of clay particles in PLACHs were investigated using wide‐angle X‐ray diffraction and transmission electron microscopy. The solid‐state linear viscoelastic properties for these PLACHs were examined as functions of temperature and frequency. The incorporation of organo‐modified silicate into PLLA matrix enhanced significantly both storage moduli (E′) and loss moduli (E″). The strong enhancement observed in dynamic moduli of PLACHs could be attributed to uniformly dispersed state of the clay particles with high aspect ratio (= length/thickness of clay) and the intercalation of the PLLA chains between silicate layers. Copyright © 2006 Society of Chemical Industry     

Comparison of the pattern of integrin expression between primary tumors and liver metastasis of gastric and colorectal cancers

To investigate the interrelationship between integrin VLA3 overexpression and liver metastasis, immunohistochemical studies of VLA3 were made in 73 cases of gastric cancer (66 cases without liver metastasis, 7 cases with liver metastasis) and 15 cases of colorectal cancer (3 cases without liver metastasis, 12 cases with liver metastasis). The rate of integrin VLA3 expression in 69 primary gastric and colorectal cancers without liver metastasis was 41%, that was higher than that (0%) in the 19 primary tumors of gastric and colorectal cancers with liver metastasis. In contrast, the positive rate for integrin VLA3 staining in 19 cases involving liver metastasis of gastric and colorectal cancers was 58% (11/19), which was higher than that (0%) in primary tumors. These findings suggest that VLA3 may play an important role in the process of liver metastasis of gastric and colorectal cancers.     

Mechanism of higher oxygen consumption rate: pressure-loaded vs. volume-loaded heart

The greater cardiac oxygen consumption (VO2) under pressure than under volume load has been accounted for by the greater ventricular wall force under pressure load. We cannot fully agree with this because the wall force has not always been uniquely correlated with VO2. We attempted to account for the greater VO2 under pressure load by the ventricular systolic pressure-volume area (PVA), which we previously showed uniquely correlated with VO2. In isolated supported canine hearts, we produced servo-controlled ejecting contractions the stroke work (SW) of which was doubled from control by doubling ejection pressure (P) with comparable stroke volume (SV) and by doubling Sv with comparable P. Despite comparable increments in SW from 370 to 680 mmHg.ml under two different loads, VO2 and PVA increased significantly more under pressure load (from 0.033 ml O2/beat and 800 mmHg.ml to 0.0560 and 1,800, respectively) than under volume load (increasing to 0.038 and 1,200, respectively; P less than 0.01). These results suggested to us a new mechanism underlying the greater VO2 under pressure load.