This paper studies the helical buckling of pipes (drillstring and tubing) in extended reach and horizontal wells, theoretically and experimentally, resulting in new equations to correctly predict and effectively prevent the helical buckling of pipes in such wells. The theoretical study shows that the so-called helical buckling load that appears in the current literature is only the average axial load in the helical buckling development process. The laboratory experiments confirm the theoretical analysis. The new helical buckling load equations are formulated by combining the theoretical analysis and the experimental results, thereby resolving the existing assumption-and result inconsistency in the current literature. The new equation predicts the true helical buckling load to be about 1.3 times the so-called helical buckling load in the current literature, and about 1.8 times the critical buckling load that predicts the onset of sinusoidal buckling. Consequently, larger bit weights or packer setting loads can be applied to increase the drilling rate or to ensure a proper seal, before the helical buckling of the pipes can occur.

The economic devastation resulting from recent natural disasters has spawned intense interest in programmes that promote regional resilience. The economic impacts of Hurricane Ike (September 2008) endured long beyond the storm's landfall, compounded by a national recession. This study analyses the pattern of post-Ike industrial growth in eight coastal counties of Texas, United States, and identifies sources of resilience and potential drivers of recovery. The results indicate that post-disaster growth patterns differ from established growth patterns. Levels of resilience vary across industrial sectors, and service sectors tend to lead a recovery. The resilience of the hotel and restaurant sector, for instance, suggests that the presence of relief workers might immunise certain sectors against a post-disaster economic downturn. Besides the sectors that are generally resilient, each county has its own distinct sectors that, depending on the extent of the damage suffered, tend to perform strongly after a disaster, owing to the characteristics of the respective county's economy.

Natural disasters result in economic losses as capital and industry are destroyed, as transportation and communication lines are severed, and as customers temporarily flee a region. In many cases, production and sales levels remain depressed as the region rebuilds. Furthermore, these direct losses account for only a portion of the total economic loss experienced. This paper presents a disaster impact model (DIM) to quantify the economic impact of natural disasters on regional output, GDP contribution, labor income, tax income, and employment, as well as the time to recovery. The model is developed to measure the impact of Hurricane Ike on eight Texas Gulf Coast counties and is then extended to a wildfire in central Texas. Actual county sales data are modeled for a period of years before the event, accounting for trends over time and between fiscal quarters, and are used to predict quarterly and annual sales by industry and agricultural commodity in post-event quarters. IMPLAN input-output multipliers are applied to the predicted sales, and stochastic estimates of total impacts are generated using Simetar. Actual postevent impacts are then compared to predicted impacts to estimate the quarterly and annual total economic losses attributable to each industry. Losses are reported at the county and state levels for individual industries as well as across the regional economy. Results show that Hurricane Ike (and a global recession) impacted the coastal economy negatively for at least three years after the event, and industries and locations exhibited different initial responses and recovery paths. Wildfire losses were more sector-specific and shorter in duration.

Biological control of postharvest diseases has been proven to be an effective alternative to chemical control. As an environmentally friendly biocontrol agent, Bacillus subtilis has been widely applied. This study explores its application in kiwifruit soft rot and reveals the corresponding mechanisms. Treatment with cell-free supernatant (CFS) of Bacillus subtilis BS-1 significantly inhibits the mycelial growth of the pathogen Botryosphaeria dothidea and attenuates the pathogenicity on kiwifruit in a concentration-dependent manner. In particular, mycelial growth diameter was only 21% of the control after 3 days of treatment with 5% CFS. CFS caused swelling and breakage of the hyphae of B. dothidea observed by scanning electron microscopy, resulting in the leakage of nucleic acid and soluble protein and the loss of ergosterol content. Further analysis demonstrated that CFS significantly induces the expression of Nox genes associated with reactive oxygen species (ROS) production by 1.9–2.7-fold, leading to a considerable accumulation of ROS in cells and causing mycelial cell death. Our findings demonstrate that the biocontrol effect of B. subtilis BS-1 CFS on B. dothidea is realized by inducing oxidative damage to the mycelia cell.

This is the first study to explore the transmission paths for liquidity shocks in China's segmented money market. We examine how money market transactions create such pathways between China's closely-guarded banking sector and the rest of its financial system, and empirically capture the transmission of liquidity shocks through these pathways during two recent market events. We find strong indications that money market transactions allow liquidity shocks to circumvent certain regulatory restrictions and financial market segmentation in China. Our findings suggest that a widespread illiquidity contagion facilitated by money market transactions can happen in China and new policy measures are needed to prevent such contagion. JEL Classification: C32; E44; E58; G01; G12; G2