Self‐healing properties of TiO2 particle–polymer composite coatings for protection of aluminum alloys against corrosion in seawater

TiO₂ particle–polymer composite coatings were applied to the surface of a 5083 aluminum alloy. After using a knife to create an artificial defect, polarization resistance was monitored in artificial seawater at a temperature of 30 °C. The polarization resistance of the specimen coated with the composite polymer containing 3 vol% TiO₂ particles increased significantly over time, suggesting that the composite coating had self‐healing properties. A carbon‐containing 2‐µm thick film was found on the coated aluminum substrate at the site of the artificial defect. The formation of the film was related to the dissolution of bisphenol A (BPA), which is a chemical precursor of the polymer coating that behaved as an inhibiting agent.     

Highwall Stability due to Punch Mining at Opencut Coal Mines

Conventional highwall mining extracts coal with an auger machine or a continuous miner from exposed seams at the base of opencut or strip operations. However, under poor strata and high stress conditions, highwall mining cannot be conducted due to pillar and roof failures. In such cases, punch highwall mining is more effective than the conventional highwall mining. This paper describes conventional highwall mining and punch highwall mining systems and discusses the stability of the highwall due to punch highwall mining at opencut coal mines.     

Characterisation of volatile sulphur-containing compounds generated in crushed leaves of Chinese chive (Allium tuberosum Rottler)

To characterise the composition of sulphur-containing constituents in Chinese chive (Allium tuberosum Rottler), GC–MS and HPLC analyses were carried out, using 12 varieties of Chinese origin, 4 varieties of Japanese origin and 6 commercially available cultivars. Five disulphides (dimethyl, allyl methyl, methyl 1-(E)-propenyl, diallyl, and allyl 1-(E)-propenyl), two trisulphides (dimethyl and allyl methyl), and two vinyldithiins (3-vinyl-[4H]-1,2- and 2-vinyl-[4H]-1,3-) were identified on the basis of their mass spectral and GC-retention data. Among the detected sulphur compounds, sulphides with a methyl group predominated over those with an allyl group. This was supported by the HPLC estimations, suggesting that all cultivars examined had much greater amounts of methiin than alliin. Also, two novel compounds were tentatively identified as [3H,4H]-1,2-dithiin and [2H,4H]-1,3-dithiin on the basis of their mass spectral features, GC-retention data, and some experimental results on their formation in reaction mixtures with different proportions of methiin and alliin. Their formation mechanism was proposed.     

Mapping of cortical areas involved in color vision in non-human primates

Foreign body (FB) injury from aspiration or ingestion is a common pediatric health problem. Diagnosis relies on clinical judgment plus medical history, physical examination, and radiographic evaluation. A multi-institutional review of 1269 FB events revealed that 85% were correctly diagnosed following a single physician encounter. However, 15% of the children had an elusive diagnosis (>1 week), despite previous evaluation. Delays in diagnosis were seven times more likely to occur in aspirations than in ingestions. Secondary injuries (e.g., pneumonia and atelectasis) occurred in 13% of airway FBs but in only 1.7% of esophageal FBs. Plain radiographs were used in 82% of children, and special studies (e.g., fluoroscopy) in only 7%. We conclude that diagnosis of FB injury in children is frequently achieved at the initial evaluation but that continued surveillance by follow-up visits to health care facilities from parents and other caretakers is important, to reduce pulmonary injuries.     

An investigation into the relationship between processing,structure and properties for high-modulus PBO fibres: part 3: analysis of fibre microstructure using transmission electron microscopy

A detailed morphological study of the microstructure of poly(p-phenylene benzobisoxazole) (PBO) fibres (HM and HM+) and a polypyridobisimidazole (PIPD) (HT) fibre has been undertaken using transmission electron microscopy. Both PBO and PIPD fibres are composed of rigid-rod polymers having p-phenylene rings in the molecular backbone and show high modulus (280–360 GPa) and high strength (4–6 GPa). It is found that the PBO HM+ fibre has the highest degree of molecular orientation of the three fibres and the longest crystal length along the fibre axis, while the PIPD fibre shows a lower degree of orientation and a shorter crystal length than the PBO fibres. To understand the effect of crystalline size and fine structure of the fibres upon mechanical properties, dark-field and high-resolution lattice images were obtained and analysed in detail.     

Positions of dorsal root ganglia in the cervical spine. An anatomic and clinical study

STUDY DESIGN: The authors investigated the positions of dorsal root ganglia and the relation of the location to symptoms and to the effects of nerve root infiltration in the cervical spine anatomically and clinically. OBJECTIVES: To clarify normal variation of positions of dorsal root ganglia and the relation of the location of dorsal root ganglia to symptoms and to the effects of nerve root infiltration. SUMMARY OF BACKGROUND DATA: The dorsal root ganglia of the spinal nerve has attracted much attention as an important structure in the mechanisms of radicular symptoms in the lumbar spine. Although the position of the dorsal root ganglia in the lumbar spine has been classified recently, there are few reports regarding the dorsal root ganglia in the cervical spine. METHODS: The positions of dorsal root ganglia were divided into two types: proximally situated and distally situated. The positions of dorsal root ganglia in the anatomic and clinical cases were compared. The relation of the positions of dorsal root ganglia to symptoms and to the clinical effects of nerve root infiltration were analyzed. RESULTS: There was no statistically significant difference in positions of dorsal root ganglia in C6 nerve roots between anatomic and clinical cases. In addition, there was no relation between symptoms and the positions of dorsal root ganglia in clinical cases. However, there was a significant difference in positions of dorsal root ganglia in C7 nerve roots between anatomic and clinical cases. Nerve root infiltration was significantly more effective in the distally situated type of dorsal root ganglia. CONCLUSIONS: This study defined the normal variation of the positions of dorsal root ganglia. The results strongly suggest that some attention should be paid to the position of dorsal root ganglia in the diagnosis and treatment of cervical radiculopathy.     

An Object-Logic model for the representation and processing of design standards

There are two distinct categories of knowledge in a design standard: (1) knowledge of the organization of design objects and (2) knowledge of the methods used in reasoning about the design objects. The object-oriented paradigm lends itself naturally to representing the organizational aspect of the design standard. The logic programming paradigm, on the other hand, is well suited to implementing the reasoning mechanisms for design and conformance checking. The object-oriented and logic programming paradigms are combined to provide a unified Object-Logic model for the representation of design codes and the processing of design standards. By storing the design provisions in a knowledge base, the model is capable of performing conformance checking and component design. To evaluate the feasibility and practicality of this model, a prototype system, HyperLRFD++, has been implemented for parts of the American Institute of Steel Construction (AISC) Load and Resistance Factor Design (LRFD) specification and tested on sample problems.     

Nonlinearity correction of brain perfusion SPECT based on permeability-surface area product model

It is well known that many cerebral perfusion tracers underestimate cerebral blood flow in high flow range. A model has been proposed to correct nonlinear relationship of flow and uptake of the tracers that accounts for the permeability-surface area product (PS model). METHODS: We examined 43 patients in this study. To test the feasibility of this method for 123I-IMP, 99(m)Tc-HMPAO and 99(m)Tc-ECD, radioactivity ratios of cerebral regions to cerebellum (C/Cr) on SPECT images were compared with those of rCBF (F/Fr) measured by PET using the 15O CO2 steady-state method. Coefficient for correction in the PS model was estimated by the least squares method, and SPECT data were corrected using these coefficients. RESULTS: Estimated PS value by this method was highest in IMP (116 ml/min/100 g) followed by ECD (66 ml/min/100 g) and HMPAO (46 ml/min/100 g). The corrected SPECT data demonstrated an excellent linear relationship, which was close to unity, with rCBF. CONCLUSION: These results indicate that the PS model can be used for nonlinearity correction of brain perfusion SPECT.     

Immunoglobulin abnormalities in epileptic patients treated with diphenylhydantoin

An immunologic study was made on 170 epileptic patients treated with antiepileptic drugs. The most noteworthy finding was that the serum IgA was decreased in 22 patients, and an IgA deficiency noticed in 12 of them. The blastic transformation rate of lymphocytes in PHA-containing cultures appeared low in seven out of 12 patients. Other findings included decreased serum IgM and IgG in some patients. These abnormalities were not encountered in epileptic patients taking no anti-epileptic drugs. Therefore, they could be considered as the side effects of antiepileptic drugs. In all patients manifesting these abnormalities, diphenylhydantoin was used in common. It was surmised that the above-mentioned immunologic abnormalities caused by anti-epileptic drugs, especially diphenylhydantoin, had resulted from disorders of the antibody producing organs in the bone marrow-thymus-lymphatic system.     

Rolling contact fatigue of alumina ceramics sprayed on steel roller under pure rolling contact condition

The rolling contact fatigue of sprayed alumina ceramics with a nominal composition of Al₂O₃–2.3 mass% TiO₂ was studied with a two-roller test machine under a pure rolling contact condition with oil lubricant. The influence of undercoating of sprayed Ni-based alloy on the rolling contact fatigue was investigated. The failure mode of all sprayed rollers was spalling caused by subsurface cracking. The undercoating did not contribute to the improvement of the rolling contact fatigue life. The elastic modulus of the alumina sprayed layer evaluated with the nano-indentation method was around 85 GPa. The depths of the observed subsurface cracks corresponded approximately to the depths where the orthogonal shear stress or the maximum shear stress calculated with two-dimensional FEM became maximum.