Ice Crystal Structure Research Articles

The Crystal Structure of Ice

The methods of X-ray analysis have been applied to ice by Ancel St. John and by D. M. Dennison. The former refers the structure to a lattice composed of right triangular prisms of side 4.74 A.U. and height 6.65 A.U.; the latter to a similar lattice of dimensions 4.52 and 7.32 respectively. The actual arrangement of the atoms is not found in either case. On certain suppositions, the arrangement can be found independently of direct X-ray analysis in the following way. Let it be assumed that each positive ion is surrounded symmetrically by negative ions, and vice versa; and in view of the low density of ice, let the number of neighbours be in each case as small as possible. The crystal is to be hexagonal, and is to have the right density. The result is that each oxygen atom is at the centre of gravity of four neighbouring oxygens, from each of which it is separated by a hydrogen atom. The dimensions of the structure agree with Dennison's figures. The conclusion is supported by a comparison between the calculated intensities of reflection and the observed intensities as recorded by Dennison.

The crystal structure of ice

Cancer is among the most serious diseases characterized by uncontrollable cell growth and spread of abnormal cells. Cancerous cells form tumors that negatively impact the functions of the body, inducing serious malfunctioning leading to fatalities in most cases. Up to now, the effective diagnosis and treatments of cancer have remained a big challenge. Nanotechnology is an emerging field encompassing science, engineering and medicine, which has attracted great attention for cancer therapy in recent years. Among the numerous nanomaterials, mesoporous silica nanoparticles (MSNs) have attracted great attention and are being considered as promising biomedical materials for the development of cancer therapies because of their size tunability, surface functionality, optically transparent properties, low toxicity and high drug loading efficiency. In this review, we first outline the properties and structure of different configurations of MSNs and their subsequent application in the field of cancer theranostics. Thereafter, the potential of MSNs as multifunctional delivery platforms for therapeutic agents and their significance in next generation cancer therapy is discussed.

The Crystal Structure of Ice

The Crystal Structure of Ice

The Crystal Structure of Ice.

The Crystal Structure of Ice.

The Crystal Structure of Ice

The Crystal Structure of Ice

The Crystal Structure of Ice

The Crystal Structure of Ice