Environmental assessment and accounting for the waste disposal stream in Bangkok, Thailand

It is very important that waste should be controlled and appropriately handled in a waste disposal stream, considering its impact on the environment. In this research, the LCA-EA model was applied to the current waste disposal stream of the BMR as well as other waste disposal stream scenarios, so that treatment cost, environmental load and environmental cost were assessed quantatively. The results of this study showed that in the current waste diposal stream in Bangkok, there were large contributions from carbon dioxide and methane to the greenhouse gas emissions from the stream. The study was able to quantify the reductions in environmental load associated with various waste disposal stream scenarios, using the baseline scenario as a standard

Repair Inspection Technique Based on Elastic-Wave Tomography Applied for Deteriorated Concrete Structures

Applying elastic wave tomography as an innovative NDT method, the evaluation of velocity distribution in three-dimensional (3D) before and after the repair is introduced in this study. The increase in the velocity with penetration of the repair material according to the repair effect is identified visually and quantitatively. The 3D tomography technique is newly proposed for one-side access inspection, using drill hammering to generate an elastic wave. Accordingly, the elastic wave velocity distribution result enables to visualize the internal quality of concrete after patch repair is successfully done. In addition, an attempt for reinforced concrete (RC) slab panels is made to confirm the effectiveness of the repair by comparing the velocity distribution of elastic waves obtained from acoustic emission (AE) tomography analysis, before and after the repair. Thus, the velocity recoveries due to injection are found in all the slab panels, and it is confirmed that the elastic wave velocities obtained using this technique can serve as an indicator for examining the state of crack and void filling with injected material. Further, a good correlation is found between the low-velocity region before repair and the amount of injection. These results show the potential of the AE tomography technique to be used as a method for estimating the effect of injection repair

Experimental techniques synergy towards the design of a sensing tool for autonomously healed concrete

The first-generation of autonomously healed concrete elements is under construction: beams (SIM-SECEMIN project, Flanders Belgium), one-way flat slabs (MeMC, VUB, Belgium) and wall panels (Materials4Life project, UK) are designed with the embedment of encapsulated repair agent. In the presence of cracks, capsules rupture releasing the agent that fills the crack void. The released agent seals and mechanically restores the crack discontinuity. This automatic process can be repeatable using vascular networks that carry the agent and release it at different locations into concrete. The innovative design is built up following several series of laboratory-scale beam tests configured over the last decade. This paper discusses the application of numerous experimental techniques that assess the mechanical performance of autonomously healed concrete: Acoustic Emission, Ultrasound Pulse Velocity, Optical Microscopy, Digital Image Correlation, Capillary Water Absorption, Computed Tomography. The study focuses on the performance and efficiency of each method on laboratory and real-scale tests. The techniques with the most promising output are selected and combined in order to design a sensing tool that evaluates healing on real applications

Clinicopathological features of advanced gastric cancer discovered after Helicobacter pylori eradication

　Helicobacter pylori infection is closely associated with gastric cancer, and its eradication is expected to prevent gastric cancer. However, gastric cancer is often detected discovered after eradication therapy for H. pylori infection. We aimed to investigate the endoscopic and clinical features of advanced gastric cancer after H. pylori eradication.　We retrospectively investigated tumor location, macroscopic and histological type, endoscopic gastric mucosal atrophy (using the Kimura-Takemoto classification), and the interval between eradication and detection of gastric cancer.　Nine patients (five males; mean age, 65.3 years [range, 44-79 years]), histologically diagnosed with advanced gastric cancer after successful H. pylori eradication between April 2003 and December 2018, were enrolled in this study.　In all cases, the cancer was located in the middle-to-upper portion of the stomach. With respect to macroscopic type, six cases were ulcerative, two were scirrhous, and one was polypoid. Histologically, all cancers were poorly or moderately differentiated adenocarcinomas. Endoscopic mucosal atrophy was mild in two cases, moderate in two cases, and severe in five cases. Two cases of scirrhous tumors developed from mild mucosal atrophy. Moreover, the tumor was detected within 36 months after H. pylori eradication in six patients (maximum: 120 months, mean: 38.7 months).　Our data demonstrated that post-eradicated advanced gastric cancers were located in the middle-to-upper portion of the stomach and were mainly ulcerative, poorly or moderately differentiated adenocarcinoma. More than half of the patients exhibited severe mucosal atrophy

A case of synchronous triple cancer of the esophagus, stomach, and colon detected by using gastrointestinal screening endoscopy

　In recent years, the detected number of multiple primary malignant tumors (MPMTs) in the gastrointestinal tract has been increasing with the advancement of gastrointestinal endoscopic equipment and the spread of endoscopic screening.　Here, we report a case of synchronous MPMTs of the esophagus, stomach, and colon detected by means of gastrointestinal screening endoscopy. The patient was a 67-year-old man who regularly visited the medical clinic for hypertension. He had a history of alcohol consumption (sake index: 250, with alcohol flushing syndrome) and smoking (Brinkman index: 800), and a family history of cancer (his father had gastric cancer).　At the medical clinic, he underwent gastrointestinal endoscopy for screening purposes. Prior observation with linked-color imaging (LCI), a type of image-enhanced endoscopy (IEE), revealed an irregular depressed lesion in the mid-esophagus. Simultaneously, an irregular, highly deformed depressed lesion and a small depressed lesion were detected on the incisura of the lesser curvature and the lesser curvature of the antrum, respectively. The esophageal lesion was identified as squamous cell carcinoma and both gastric lesions were identified as well-differentiated adenocarcinoma.　The patient was referred to our hospital for further examination and treatment for esophageal and gastric cancer. Subsequent colonoscopy revealed a well-defined, ulcerative tumor in the transverse colon. First, endoscopic submucosal dissection was performed for the esophageal lesion, followed by laparoscopy-assisted distal gastrectomy with D1+ lymph-node dissection and transverse colectomy with D2 lymph-node dissection for the gastric and colorectal lesions, respectively. Histopathologically, the main gastric and colonic tumors were in advanced stages; fortunately, the esophageal cancer was an early-stage lesion (7 × 5 mm, 0-IIc, pT1a-LPM, INFa, ly0, v0, pCurA), which has a much better prognosis than advanced esophageal cancer.　In patients with multiple cancer risk factors (alcohol consumption, smoking, and family history), it is important to consider the possibility of MPMTs. Furthermore, upper gastrointestinal observation combined with IEE, such as LCI, may be useful in the early detection of lesions

Wave propagation in cementitious material containing artificial distributed damage

The propagation of ultrasonic pulses through highly inhomogeneous mortar is discussed in this paper. The inhomogeneity is introduced by light plastic inclusions in different volume contents to simulate distributed damage. Wave propagation in such media becomes dispersive and therefore, although pulse velocity is influenced, other easily measured features are much more indicative of the inclusion content. These features can certainly improve characterization since they include information from the whole waveform and not only the leading edge

Global Monitoring of Large Concrete Structures Using Acoustic Emission and Ultrasonic Techniques: Case Study

Global monitoring of civil structures is a demanding challenge for engineers. Acoustic emission (AE) is one of the techniques that have the potential to inspect large volumes with transducers placed in strategic locations of the structure. In this paper, the AE technique is used to characterize the structural condition of a concrete bridge. The evaluation of AE activity leads to information about any specific part of the structure that requires attention. Consequently, more detailed examinations can be conducted once the target area is selected. In this case, wave propagation velocity was used as a means to evaluate, in more detail, the condition of the region indicated by the AE analysis

Elementary study on evaluation of environmental loads and costs for waste treatment system in Bangkok

It is very important for waste to be controlled and appropriately treated in a waste treatment system because of its impact on the environment. This study quantitatively evaluates the current waste treatment system and suggests countermeasures based on their impact on reducing the environmental and treatment costs in order to solve waste treatment problems in Bangkok, Thailand. Evaluation models are applied to estimate the treatment and environmental costs in the current waste treatment system. This study shows that the contribution of carbon dioxide and methane gases from the current waste treatment system in Bangkok, Thailand to the greenhouse effect is large. Using the baseline scenario as a standard, the study provides a quantitative measure of the reduction in environmental costs that can be achieved by applying the countermeasure scenarios